# British Seagull motor rebuild?



## Chris152 (31 Aug 2018)

My son found this in a shed at his gran's house yesterday. It's a Seagull outboard that's been in the shed 40 years since last used, and wasn't prepped for storage and the shed's pretty damp. The prop turns, and things on the outside that are supposed to move, do. He wants to try to rebuild it, but I'm wondering if that's likely to be possible without spending a fortune.









I found this website
http://www.saving-old-seagulls.co.uk/index.html
but before getting involved with any detail wondered if those of you who know about restoration of old motors had any thoughts?
Thanks for any thoughts.
Chris
edit - he's itching to start taking it apart today - is it a bad idea to just start stripping it down, or can he get on with it so long as he keeps a photo record of where each part comes from? I've no idea about these things.


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## novocaine (31 Aug 2018)

1. remove the spark plug , can you turn it over by hand?

if yes, then remove the fuel tank, rig up a temporary tank and put about 100ml of fuel oil mix in it (2 stroke baby), pull over with the plug out, if you get fuel in the cylinder, pull it over a few more times then walk away for 10 minutes.

2. check the plug fires (stick it in the cap and pull the engine over with the plug resting on head, look for the spark) if you have a spark put it in the hole and try to start it, you'll be pulling like a monkey at the zoo but it might start. if it does, yey, now strip it and clean everything, if it doesn't booo, still strip it but now you're in to diagnosis of issues (if you have a spark, it's the carb, strip, clean, etc).

is it worth rebuilding? hell yes, and it gives your son something new to learn, it won't cost the earth to get it running, you'll need gaskets, pipes, rubber bits as they will all be dead, I'd have thought and assuming nothing is broken a good clean and rub down of parts covered in oxidization maybe all it needs, a splash of paint won't hurt. parts for the carb are dirt cheap if needed, assuming it turns over there isn't much in the engine itself to go wrong (rings maybe gummed up and need cleaning or replacing).


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## Chris152 (31 Aug 2018)

Thanks Novocaine. 
1. What's the reason for using a temporary tank? I wouldn't know how to do that! If we flush the old one a bit would that be ok?
2. Should the plug actually spark to the head? (Didn't understand why it needs to rest on the head...)

Don't worry, you won't have to coach us through every step, I'll take this to a seagull forum if it looks like it's do-able! But it'd be great to do the checks you've suggested just to know what shape it might be in. And what you say about him learning is the bottom line, he really wants to do a motor bike but i'm not so keen on that...
Cheers
C


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## custard (31 Aug 2018)

Is it worth rebuilding?

Absolutely! Down here on the Solent there are loads of Seagulls still chugging along. They're like Morris Minors or Land Rovers, bomb proof and everyone feels better for just seeing one.

https://www.britishseagull.com/technicaltips.php


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## Chris152 (31 Aug 2018)

Thanks for that custard. The paragraph (in your link):
'Apart from fresh fuel (as above), it is the corrosion caused by storing the engine somewhere warm, after use in salt-water, that does the damage. Usually cleaning the magneto and coil contacts and cleaning and re-gapping the spark plug and contact set is sufficient to regain the spark.'
adds to what novocaine's written and will give us something positive to work on today - once we've brushed, vacuumed and just looked at it for a while, which we can just about manage without searching additional info on the net!


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## mbartlett99 (31 Aug 2018)

Dads got one from 1947 - they're like cockroaches, will survive a nuclear blast. Hell, the pipper might even start up off the bat. And they are worth reselling too.


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## novocaine (31 Aug 2018)

temporary tank, also known as a pop bottle and a bit of tube to the carb.  because that tank is steel and rusty right now, you don't want to pull in rust, also, 20 years, with fuel that sucks up water, you might find it's a bit leaky. I assume you've got some 2 stroke oil, not sure what the mix is for these little things but 2-1 is a good place to start (reckon the seagull forum will tell you though).

the plug needs to be earthed, hence resting on the head, it will spark across the gap of the plug. if it doesn't spark it maybe the plug (we'll test that once we know if it sparks) it could be the magneto or the coil or the HT leads, all easy to check but a quick test first saves tearing stuff apart. 
3 rules of engine diagnostics (not including the obvious, is it turned on). does it turn, does it spark, does it get fuel. everything else is a nuance.


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## novocaine (31 Aug 2018)

if you want to do something that feels like you've achieved, take all the stuff that isn't engine related off (like the handle and such) and get him cleaning it with wire wool and WD40 (because it is the elixir of life and every striving young mechanic should learn to love the smell).


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## Chris152 (31 Aug 2018)

Ok, test as per the photo (the block's buried under the fuel tank and starter thingy, so it's on the fuel tank which is completely dry) and no spark so far when I pull the chord.




The plug's a weird one with the top bit of metal arranged to the side of the centre (based on vague memories of working on cars when I was younger!), so I'm guessing if it's faulty it'll be mail order. 



novocaine":1df9v97n said:


> if you want to do something that feels like you've achieved, take all the stuff that isn't engine related off (like the handle and such) and get him cleaning it with wire wool and WD40 (because it is the elixir of life and every striving young mechanic should learn to love the smell).


That's great - I'll get him started on that. I've said we'll do this as a winter rebuild to manage his impatience, but it's good to get some momentum at the start.

oops - just realised we've started with your second task - I don't have any tube to start on the first, we'll head out later to get some.


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## novocaine (31 Aug 2018)

the tank is probably not earthed and it's painted so you aren't going to get a good contact. get a pair of pliers and holding the plug cap with them, hold the plug against the head (the bit the plug came out of). 
an off centre electrode was an attempt to get a cleaner path for a spark, you can fit a standard plug in there easy enough. 
if that doesn't work, select your least favorite screw driver and jam it in the plug cap (remove the plug first), hold the handle not the metal the put it about 2mm from the head and pull the engine over, if there is any live it will spark to the head and the plugs dead, if it doesn't, clean the magneto, which means pulling the starter real off. 
this is a great chance to give your son a jolt and teach him that sometimes it's dangerous to play with electrickary. 

Edit, that tank looks like it's ali, so give it a good swill out and you'll be fine, but do replace the pipe, it's fecked.


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## Chris152 (31 Aug 2018)

What's your hourly rate for online tutoring, novocaine? No spark - but the boy wonders if the whole thing's not earthed? This is how we're holding it, and it looks like there's ali between the block and the vise - should the prop be touching the floor?


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## sunnybob (31 Aug 2018)

Just to expand on novocanes message a little bit;
Use insulated handle pliers, because although theres no amps to kill you, 20,000 volts stings a little bit! :shock: :shock: 
Hold the plug with the pliers, hold the THREAD of the plug firmly against a bare metal part of the head. Then carry on as above. 8)


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## Chris152 (31 Aug 2018)

Thanks Bob - the pliers have plastic handles (= insulated?) but wouldn't reach around the plug cover, so I attached a 'hinge' to the cover so I could hold it with the pliers. So hopefully safe, and I'm doing the holding while he does the pulling. 
On the earthed/ not earthed question, Could I hold the plug against the metal vise on the bench instead of on the block?

aha - and hold the thread against the block - i was holding the outer metal bit of the plug. God, we're both learning lots here.


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## sunnybob (31 Aug 2018)

You have to have a circuit for ALL electrics to work. The engine block is the circuit.
magneto, lead, plug, engine, magneto.
A separate piece of metal will never give you a spark


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## novocaine (31 Aug 2018)

edited because I got all out of order.
ok earthing is a bit of a misnomer, sorry. 

the engine itself is the earth in this case but if it helps we shall call it negative. 
no spark, for what it's worth, give it about 20-30 pulls without the plug in then test again, they can take a few cranks to get the old juices flowing and a spark to get going if they've been laid up for a while.
then check the points, under the fly wheel so remove the start real and the flywheel and look for where the HT lead goes, pull the top of and you'll see the points, check the gap and clean the contacts with a little bit of emery paper (gap is 0.5mm apparantly)

as your in there clean the fly wheel and the magneto.

also, once it's got a spark you really need to start it with the prop in a bucket of water.


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## novocaine (31 Aug 2018)

just had a chat with the captain (not really a captain, but he wears the nickname well fora guy with a dingy), he said stick a socket on the flywheel nut, attach a drill and spin it for something like 5 minutes at as fast as the drill can handle. pulling it by hand 30 times is hard work, let the drill do it instead.
edit: also, you're going to want to pull it so hard it nearly falls of it's mounts, at which point as it teatters on falling in your bucket it will decide to start and you'll be grabbing for it to stop it before it falls off. his words not mine.


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## Chris152 (31 Aug 2018)

Earth/ negative circuit understood (well, sort of)! Getting the flywheel off was a palava all of its own but we managed without breaking it, cleaned the points and the boy's now headed off to the shops to buy a feeler gauge. We did the 30 pulls trick (well, he did) but will try the drill option if still nothing. And got the starting up/ bucket/ strong mount point! Don't want it waving about in the air if we manage to get the prop running... FWIW, he's loving this and learning all the while.


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## sunnybob (31 Aug 2018)

Text him quick to buy a new spark plug while he's there. 4 quid at most.
Raed the number off the side of the plug for him to get the correct size.


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## novocaine (31 Aug 2018)

first lesson, a fag packet is about 0.5mm thick.  so now he's getting a motorbike and learning how to smoke, oh how they grow up so fast. 

captain said something about clean the coil and the contacts to it. the reason for spinning it was something about building magnetism in the flywheel.


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## Chris152 (31 Aug 2018)

He was back before I could call him about the plug - they didn't have a feeler gauge anyway (local hardware store, think four candles/ fork handles, brilliant shop but a dying breed). Which means Halfords, I guess, and that means a trip out later so probably end of play for today. The plug has 8 COM written on it - is that the info they'll need to replace it? 
And yea, fag packets and motorcycles, just what we need. :shock: ha.
Meanwhile, we've made great progress with cleaning up the handle a bit...




Think you'll have to agree we've made spectacular progress with that. 
Thanks all for your patience, lots learned so far.


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## novocaine (31 Aug 2018)

much better.  2 thickness of 270gram card stock or 1 business card.


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## nev (31 Aug 2018)

(Champion) 8com is indeed the plug number and a tad unusual, check here for a list of alternatives
http://www.gsparkplug.com/1x-champion-s ... gotoupsell


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## novocaine (31 Aug 2018)

I don't think there will be much wrong with the plug, I think it's more likely a lack of magnetism in the flywheel from sitting for so long and various dirty contacts in the LT side.


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## Chris152 (31 Aug 2018)

nev":73t89aqo said:


> (Champion) 8com is indeed the plug number and a tad unusual, check here for a list of alternatives
> http://www.gsparkplug.com/1x-champion-s ... gotoupsell


Thanks Nev. The plug connects to the holder using a screw thread - will they all have that, and is there likely to be a metric/ imperial problem, or are all threads the same? And when it says alternatives, does that mean any of those would work ok?



novocaine":73t89aqo said:


> I don't think there will be much wrong with the plug, I think it's more likely a lack of magnetism in the flywheel from sitting for so long and various dirty contacts in the LT side.


I really wanted to try spinning the flywheel but couldn't figure how to connect a socket to the drill! We tried a bit of wood held by a screw and driven by a screwdriver attachment but the screw thread tore through the wood after a couple of turns. WHat would be a better way of connecting them?

Thanks.


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## novocaine (31 Aug 2018)

I have an extension bar that fits in a chuck, I guess others don't. 

how about a piece of hardwood cut square to suit the socket then roundish to suit the drill chuck?


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## Chris152 (31 Aug 2018)

Yep! With the sheath knife he made/ put a handle on recently we whittled the square end of a piece of oak to round and hey presto...





We thought maybe if we can't get it running properly, we just take a cordless drill with us when we head out to sea. (Can't claim credit for that idea, saw it on a Seagull forum.)
Sadly, no improvement on the sparks. Definitely going to try a plug if we can get the right one.


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## Beau (31 Aug 2018)

Thats a much better way to spin up a Seagull. Remember my dad nearly knocking my mums teeth out with a the old rope starter


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## nev (31 Aug 2018)

Chris152":13zxguzo said:


> Thanks Nev. The plug connects to the holder using a screw thread - will they all have that, and is there likely to be a metric/ imperial problem, or are all threads the same? And when it says alternatives, does that mean any of those would work ok?



I would imagine that any of those listed would physically fit (i.e. the correct thread of the correct length that screws into the head and have the correct electrical resistance) but some may have a solid top to use a different cap. (Some plugs have a solid top and others the solid cap connector unscrews to reveal the thread.) As long as it has a thread-on top I would guess you're good to go. 
Googling The NGK AB-6 AB6 (2910) it comes up as listed for a seagull on e.g. eBay.


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## Suffolkboy (31 Aug 2018)

Beau":1rt3snro said:


> Thats a much better way to spin up a Seagull. Remember my dad nearly knocking my mums teeth out with a the old rope starter



I have dodged either my Dad's fist clutching the plastic handle or the rope as it came whipping past my head more times than I care to remember, we used to borrow an old Seagull outboard to put on the dinghy to go fishing, looking back I think rowing there might have burned less calories than starting the outboard!


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## powertools (31 Aug 2018)

Really interesting thread please keep us informed with progress.
I think that if you clean the contact points and introduce fresh petrol it may well start.
If you are not used to working with engines be prepared for a suprise when it starts and make sure you know how to stop it.


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## Keith 66 (31 Aug 2018)

Aah stopping it. My dad had one, it leaked oil everywhere & left an oil slick on the water. They get carbon'd up easily & then will run on when you shut the petrol off. Basically running on excess lube oil.
Dads one did this & the only way to stop it was to face it grimly & make a firm powerful grab for the flywheel with both hands thereby stalling it.
We did run a Seagull outboard race at the yacht club years ago & it was great fun.


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## mbartlett99 (1 Sep 2018)

Bin bag over the air intake, works on a runaway 2000kw diesel. Did have to change my pants though.


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## sunnybob (1 Sep 2018)

Bath plug. On a chain, connected to the frame near the carb. Stuff the bath plug in the air intake.

Used to do that on big old motorcycle engines.


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## novocaine (1 Sep 2018)

The air filters a brass trumpet with a bit of wire mesh in it. Shut the choke and put your hand over it. If that doesnt stop it pull the cap off the plug. 

If all else fails push it over the side, theres a few of these at the bottom of various lakes.


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## Chris152 (1 Sep 2018)

Have to admit, I've no idea how you're supposed to stop it - can you imagine? I'd probably have waited til it ran out of fuel. But that's some way down the line, we're still working on the spark bit of the 'does it turn, does it spark, does it get fuel' guide. 

I called and spoke with the chap at Classic Seagulls about the spark plug as there seem to be different lengths of the same plug and apparently if it's too long it'll interfere with the gubbins (hit the piston?). So I've got a new plug on order, and he suggested a new low tension wire at 50p as he said these are often the first problem to look for as they move around. 

One thing he said that was incredibly helpful was that it's best not to crack open the crank case (we now know what that is having watched a youtube video on how to work on one) nor to remove the engine block as gaskets for these are no longer available new - good job we didn't just go ahead and strip it down at the outset. Apparently the head gasket is fine to replace. 

Reading your comments about seagulls is funny - dad used this to power the mirror dinghy he built with my brother (I was too young to be involved) and I still remember the feeling as it powered us around the waters of South Devon and the river Avon in Wiltshire. I also remember the day we didn't have it and I managed to drop a rowlock into the water in a deep channel and having to wind our way back somehow to shore. Happy days.

ps Nev - the plug I ordered is a NGK AB6 and apparently there's another that's compatible but I can't remember who makes it. Thanks.


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## sunnybob (1 Sep 2018)

There should not be different lengths of spark plug with the same number, that negates having numbers. measure the length of the thread to make sure you get the right one.

DO NOT yank the plug lead off unless you are wearing insulated gloves or have a lump of dry rag, and even then not if you have a pacemaker. having stopped several engines this way in the dim and distant past, 20,000 volts up your arm is a feeling that stays with you forever.

I dont know this particular engine, but magneto units usually have an earth wire connected to the bolt in the centre of the points cover, which "should" lead to a flip switch and then onto earth (ground) to kill the circuit.

apart from head gaskets, which are normally copper / paper laminates, any other gasket will be thick paper, which can nowadays be replaced with a silicone gasket goo.


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## Doingupthehouse (1 Sep 2018)

Hi,

You may already be aware of this, but Sheridan Marine stock most spare parts and workshop manuals for British Seagull motors. 

https://www.sheridanmarine.com/category/british-seagull-outboard-spares

Simon.


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## Chris152 (1 Sep 2018)

sunnybob":1iasb2sv said:


> There should not be different lengths of spark plug with the same number, that negates having numbers. measure the length of the thread to make sure you get the right one.
> 
> DO NOT yank the plug lead off unless you are wearing insulated gloves or have a lump of dry rag, and even then not if you have a pacemaker. having stopped several engines this way in the dim and distant past, 20,000 volts up your arm is a feeling that stays with you forever.
> 
> ...


Thanks Bob. I got confused about the plugs, which isn't surprising - so called Classic Seagulls to be sure I was getting the right thing, which is this:
https://www.classicseagulls.co.uk/index ... oduct_id=3
I'd searched the net and found this, which seems to have the same numbers but which has more thread/ looked longer than the old one on the motor? 
https://www.amazon.co.uk/NGK-SPARK-PLUG ... B000CSGX3I
That made me unsure what I was doing - and I guess it's confused as I'm not getting the same as the original, just one that's compatible. I'm sure I'm missing something. 



Doingupthehouse":1iasb2sv said:


> Hi,
> You may already be aware of this, but Sheridan Marine stock most spare parts and workshop manuals for British Seagull motors.
> https://www.sheridanmarine.com/category/british-seagull-outboard-spares
> Simon.


I'd seen they have a workshop manual on Seagulls, reckon it's worth getting - the boy tends to do everything by phone which works ok most of the time, but it's not the same as having it there on paper, making your own notes and that. Well, that's what I reckon. Cheers.


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## Mark A (1 Sep 2018)

I found a Seagull motor a few years ago. A neighbour moved out the same day we were going on holiday for a month. Came back to find a Seagull propped up against their fence. The house was still unoccupied, so asked round and nobody knew where it came from. I put the motor in my garage to shelter it from the weather, and stapled a note to the fence in case the owner came looking. No one ever did, so when I moved house a year later I took it with me, and now it's in my attic for when I have the time to restore the motor and put it to use. 

I did toy with the idea of mounting it alongside my little 4stroke 2.5hp Yamaha, but on a 12ft inflatable there wouldn't be a lot of room. Maybe on a kayak instead? It's light enough.


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## sunnybob (1 Sep 2018)

According to google, champion 8COM equivalent is a D16.
If you cant get that, here is a bewilderingly long list of equivalents.
http://www.sparkplug-crossreference.com ... AMP_PN/D16

Find out what manufacturers plugs are available near you. maybe print the list and take it (and the old plug) with you, although any shop selling plugs should have a comparison chart.

The thread length is of PARAMOUNT importance. Its a short thread. If you fit a long thread it will punch straight into the piston crown on the first swing.


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## Chris152 (1 Sep 2018)

Yes, D16 is the other plug the bloke said was good for the job. 

On the gaskets, am I right thinking





A is the cylinder head gasket;
and B is the engine block gasket?
C is the crank case join according to the video I watched yesterday - which showed it being re-sealed with goo.

AND - can the goo that's used in place of gaskets work instead of a cutout gasket? Just wondering in case going ahead and separating the block is an option - it'd be nice to take it apart completely, but not if we can't put it back together properly.


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## dynax (1 Sep 2018)

Hi Chris, i have 2 seagull motors, and i would advise against stripping down too far, there is no need really, when i got mine, i left some neat petrol soaking in the cylinder head for a while, replaced the spark plug, checked the points, and after a bit of clean, tank, carb, pipes etc, put it back together, put some fuel in, and it went on the fourth pull, just make sure you have it in a bucket of water before you attempt to start it, it needs the water to cool down the engine, good luck with it,

forgot to mention, get some fresh gear oil in it too, i think it's EP90, but double check,


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## novocaine (1 Sep 2018)

Head, base, crankcase. In that order. No reason to seperate unless it's a rattling like a bag of spanners once running.


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## novocaine (1 Sep 2018)

Sae140 not ep90. Close though and wont really make much difference.


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## novocaine (1 Sep 2018)

Do you have a multimeter? 
Pull the ht lead of at both ends and test it for continuity. Do the same with the lt wire. Till ypu have a spark it's pointless looking at anything else. Have you do the screwdriver spark test?


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## Chris152 (1 Sep 2018)

Mark A":1x4k3u0w said:


> I did toy with the idea of mounting it alongside my little 4stroke 2.5hp Yamaha, but on a 12ft inflatable there wouldn't be a lot of room. Maybe on a kayak instead? It's light enough.





dynax":1x4k3u0w said:


> i would advise against stripping down too far, there is no need really, when i got mine, i left some neat petrol soaking in the cylinder head for a while, replaced the spark plug, checked the points, and after a bit of clean, tank, carb, pipes etc, put it back together, put some fuel in, and it went on the fourth pull, just make sure you have it in a bucket of water before you attempt to start it, it needs the water to cool down the engine


There's a dilemma. We got into this so my son could dismantle and rebuild an engine, I don't think it mattered to him what the engine was for. The more I think about it, the more I want to use it. We have a kayak, and have talked about building a canoe from ply. On one hand, it's about him learning how an engine works; on the other, it's becoming about using it. Pulling it all apart is about him learning; getting it working is about that but less so if we don't dismantle it completely, but also about using it (which I now really want to do!). Based on your comments, I reckon leaving the crank and block alone might be the way to go. 
And SAE 140 it is!


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## Chris152 (1 Sep 2018)

novocaine":gtc9vvpv said:


> Do you have a multimeter?
> Pull the ht lead of at both ends and test it for continuity. Do the same with the lt wire. Till ypu have a spark it's pointless looking at anything else. Have you do the screwdriver spark test?


No, would this do the job? 
https://www.screwfix.com/p/lap-mas830b- ... 3godwg8EGA
tbh I was afraid of the screwdriver test, thought I might end up with those 20000 volts passing through my heart?!


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## dynax (1 Sep 2018)

yep, my mistake 140 it is, i haven't used mine for a while so easy to forget, i know what you mean about wanting to use it, and also as a project for your lad, if you get it running and all is ok then use it, but if doesn't run as it should then do a full strip down and rebuild, nothing to lose and also gets into problem solving first,


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## dynax (1 Sep 2018)

something like this might be handy https://www.screwfix.com/p/laser-ht-lea ... tid=424634


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## novocaine (1 Sep 2018)

Unless you have your hand on the engine or your feet in the same water you aren't getting a a shock. Remember that circuit thing? It may try to go to ground through you, a rubber mat will stop that. Also, safe side, dont hold the metal part. 

That meter will do you fine. You can do continuity test with a 9v battery and a bulb if you havent got a meter and dont fancy buying one. 

Having sat and thought about this a bit i think the simply stuff to rule out is the lead and caps by taking the cap off the lead ( they unscrew) cutting 10mm of the lead and fitting the cap back on. Both ends. Lt side test the wire. Points,plug, coils in that order.


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## novocaine (1 Sep 2018)

You dont need to pull it apart to learn how it works and i reckon hes getting a lot more from it by problem solving, i sat with a physist a few weeks ago, he could explain how it all worked but couldnt fix it if broke, (we were discussion suspension, dont ask why)


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## powertools (1 Sep 2018)

I did a long reply but some how lost it and have now run out of time.
The spark testers from Screwfix are of no use in this situation you would be far better of with something like this.
https://m.ebay.co.uk/itm/Ignition-Spark ... r=1&_rdt=1
You would be able to not only see if the plug is at fault or if the problem is in the ignition system.


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## novocaine (1 Sep 2018)

All of which would be solved with the screwdriver. Lol


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## Andrewf (1 Sep 2018)

I have a very rough and elderly seagull. Which I used lots in the 80's then replaced it with a nicer mariner. The seagull got chucked in the back of the shed and forgot about. About 5 years ago the mariner finally gave up the ghost, and in desperate need of an outboard, I dragged the seagull out. Took couple of days to clean all the cobwebs and sawdust off. New spark plug, some new gear oil bit of a clean and away it went. It's one of the old ones that runs on 10.1 so oil leaks everywhere. I have seen some brilliant things with seagulls, my favourite being watching one of my uncle's going past in his dinghy and filling the tank with some petrol. He must have spilt some as the next thing was it all on fire and he was trying to splash water on it to put the fire out. While the engine was still running and his dinghy careening about out of control.


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## Eric The Viking (2 Sep 2018)

From biking, I really like the NGK plug caps, the ones that don't take the Champion-style screw-on aluminium pimple on top of the plug. if the plug cap connects to the thread on the top of the spark plug directly it's one less thing to make a poor connection and weaken the spark. NGK caps also have a rubber seal round the spark plug's ceramic insulator, which is probably handy on an outboard.

IIRC, plug caps come in two sorts, one with a suppression resistor (to stop radio interference), and one without. You probably want the "without" version, but check your new service manual! Officially it doesn't make much difference, but with magneto systems, I think the simplest path for the spark is probably best. Replacing the plug cap is a cheap bit of maintenance, and goes a long way to giving you a solid spark at starting. 

Also, if it's really old, replace the suppression capacitor ("condenser") across the points gap - it's usually a silver cylinder close to the points, probably mounted to the same plate. They do age - it might be fine, but a new one is one less issue lurking (and they shouldn't be expensive). 

Obviously outboards get damp, so "tracking" of the high voltage down a path you don't want (e.g. across the cylinder head instead of through the plug), would be something to watch out for. Keep the high-voltage side clean, and water free (as much as possible), with Vaseline or WD40, although the latter is less permanent. If you can't get a good spark whilst holding the plug to the metalwork (with the HT lead connected to it and you with gloves on!), check in dim lighting in case it's tracking somewhere else at the same time.


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## powertools (2 Sep 2018)

novocaine":2iaqc8u8 said:


> All of which would be solved with the screwdriver. Lol



I did not suggest that the theory was incorrect but in practice trying to maintain a small gap between a screwdriver and a cylinder head while pulling on a starting rope to try and see a small spark is not going to work.


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## Robbo3 (3 Sep 2018)

powertools":1c0w4o7d said:


> novocaine":1c0w4o7d said:
> 
> 
> > All of which would be solved with the screwdriver. Lol
> ...



I'm not sure to whom novocaine was replying but I took it to mean that the engine was easily stopped by placing a well insulated screwdriver across the plug & the body to earth it out.


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## sunnybob (3 Sep 2018)

If the plug is inserted into the engine and the engine is running, it cannot be stopped by earthing out the plug body, because the plug body is already earthed to the engine.

The sparking circuit (low tension or high tension) has to be interrupted to stop the spark. You can earth out the low tension circuit or rip the plug lead off. If the plug is heavily carboned then the engine can "run on" by itself as the carbon is glowing and igniting the fuel without a spark being present.

The "screwdriver trick" is a way of checking the integrity of the high / low circuit without using a spark plug. Its a quick and dirty "side of the road" trick to help diagnose a fault quickly (is it the plug? is it the points?). I've used it on motorcycle engines long before they had electric starters, so although tricky, it should still be possible to do with a corded pull motor.
Remember, youre not trying to spin the motor a dozen times to get momentum, you just need to get the ignition system turning over, something that on a small two stroke without a plug in, is as easy as it can get.


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## novocaine (3 Sep 2018)

1. Powertools. Screw driver trick for testing a for a spark, I've managed to do it on a hell of a lot of englne's over the years ranging from tiny little lawn mower 2 strokes to 500cc twin opposed westlakes, all of which had pull starts on and all of which I've managed to do it on, so yes, I still say you can use a screwdriver instead of wasting money on a gimick that does it for you. but hey, that's just my opinion, I wasn't blasting your suggesting, just reiterating something I said right at the start of this thread as part of me trying to help Chris and get his seagull running for minimal outlay. Also, thanks Robbo for coming to my rescue (using a phone at the weekend makes for difficulties in using the quotes. 

2. Bob you are right earthing the body won't. but earthing the plug will kill the engine, the pixies are lazy and want to take the shortest and easiest path to earth, if you earth the nipple with something it will take that path rather than jumping the gap, it's how atcos and qualcast mowers were stopped for years. (piccy below shows the tab you pushed down to do it, never got electromucited doing it either). none of this is relevant here though as that isn't what I was referring to by saying use a screwdriver (see point 1) and you couldn't do it here anyway because it's an enclosed cap.







I've already said how you stop it, it's the British Seagull suggested method, yes you could put a "kill switch" in to the LT side of the circuit, something to thing about in the future, once it actually runs, but don't forget the choking it method, as one day that switch will fail (salt water sucks)

sitrep needed Chris, are you waiting on parts or digging in further?


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## Chris152 (3 Sep 2018)

novocaine":2w00c7xj said:


> sitrep needed Chris, are you waiting on parts or digging in further?


Ha, yea I went quiet as lots of this went right over my head! The boy's not here for a few days, and the new plug arrives mid-week, I think. My cunning plan is to wait for it and him to arrive/ return, fit the plug and see what happens. Then, if that doesn't do the trick, we'll work back through the advice above. But - we're going to read through it together anyway - it clearly contains lots of info/ terms we need to learn and read up on. 
It's great reading through the suggestions, if you all have the patience to keep responding to problems as they crop up I'd like to keep the rebuild here rather than head off to a Seagull forum.


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## novocaine (3 Sep 2018)

Chris

if you're playing with it today, pull the HT lead off, clean all the contacts (both ends of the lead and where it attaches to the coil. remove the fly wheel and clean the big metal bits either side of the coil, if you got a multimeter, put it in ohms, put one end on the contact that goes to the HT lead and the other to the body of the engine, you should see 3-5k (so you'll want to put the meter in the right range to show you that thousands) if you haven't got a meter yet, don't worry about it, I'd be surprised if the coils dead. be nice to know if it's a villers or a wipec coil and points system too (again, age dependent).

you got a post in before me.  
as above, but once the young apprentice is back.


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## Chris152 (3 Sep 2018)

Thanks novocaine, will wait for the apprentice! And it's wipec, apparently...


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## novocaine (3 Sep 2018)

I'm guessing (because youth does this better than the rest of us) you've seen this YT channel, but in case you haven't.

https://www.youtube.com/user/barjhealy/videos

lots of very good info on here, most of which we have already covered but still.  nice run down of the HT lead and how to strip it for cleaning.


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## sunnybob (3 Sep 2018)

Novocaine... agreed. I was of course refering to a plug with a covered cap. Thats why I said "earthing the BODY" will do nothing.
If its an open top connector, then that could be shorted to earth.

I have far too much experience on 4 stroke motors, but absolutely zero on 2 strokes (horrible tinny things :shock:  ), so if I go quiet you'll know I'm out of my depth.


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## novocaine (3 Sep 2018)

As you might have guessed Bob, I wrote something then noticed you'd said body, so a quick amendment was made.  
I grew up with 2 strokes, my first bike was one (I don't count a c50 as a bike  ), the hovercraft had a pair, so did the kart and the dingy had one too, I've spent 2 long replacing pistons, sleeves and heads because I've run them to hot to care to mention and most likely done every dirty trick you can imagine (and some you hopefully can't) to get the pippers running or to eek out a couple more ponies. these little single cylinder 100cc jobbies are so simply that they rarely fail and your unlikely to get out your depth here luckily. now repeat after me, suck squeeze bang blow.  or in 2 stroke terms, suck squeeze pipper it, hit it with a hammer, pray to the gods of petrol, kick it, scream at it, start again.


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## sunnybob (3 Sep 2018)

Back in the 60's I had a friend with an ariel arrow 2 cylinder 200 cc two stroke (I actually passed my test on a borrowed ariel leader after blowing up my bike the week before). 
There was a very old joke at the time about a biker riding blind in the mist, saying to his passenger "its either a thick fog or we're following an ariel arrow"
That wasnt a joke. We always insisted he rode at the back. And his tool kit consisted of a plug spanner and 10 assorted plugs.
No ta, I'll stick the 4's. :roll: :roll:


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## novocaine (3 Sep 2018)

bet he learned to ride with 2 fingers on the clutch lever too, in case it nipped up.  

very little beats the smell of Castrol TTS on a cool misty morning, a rather evocative smell normally associated with race meets and 15k red lines on teeny tiny lightweights. actually thats not quite true, the sound of silence than rains over the open paddock at lunch time of said race meet is right up there too :lol: .


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## sunnybob (3 Sep 2018)

wrong castrol.
A 1963 BSA 500cc dbd gold star, running castrol R in the engine, with a tablespoon of R in the petrol tank.

mmmmmmmmmmmmmmmmmmmm, you can keep yer 2 strokes =D> =D> =D> =D> =D>


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## Chris152 (6 Sep 2018)

Quick update. The new plug made no difference, still no spark. I borrowed a multimeter, tested the cable leading to the plug for continuity, fine; tested the coil as per this vid 
https://www.youtube.com/watch?v=7qU8slqE2Jc
fine (I think, though the meter reading kept hopping all over the place, but it came in at between 3.5 and 5 mostly - probably user error). Cleaned the contacts at both ends of the lead. So next we're going to clean everything inside the flywheel and replace the LT wire, re-check all the gaps (I still don't have a feeler gauge but will borrow one), and see where we get to.
We had found a couple of videos by Coastal Works novocaine, but hadn't seen the index page that you linked to - that's brilliant, really clear videos and covering most of what we need, I think.
He's back in school now which is slowing things down, and I'm getting impatient! I guess I can do some of it while he's not here and retrace the steps but feel like I'm cheating...
Ta
C


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## Eric The Viking (6 Sep 2018)

Be very systematic/methodical and check everything to a known-good state as you go. You seem to have narrowed it to the electrics, now you're finding the component that's broken (and there may be more than one.

You should get a healthy spark, by holding the end of the HT lead (no plug cap nor plug) on the cylinder head or cylinder barrel (any part of the main casting you can reach would probably work). just push it down close to the top with a plastic ruler or similar, so the plug end of the lead is next to the metalwork - the spark should jump across the end of the cable easily. If that works, it implicates the plug cap (get NGK replacement, as I said earlier!), but it's not unknown for new plugs to be faulty, too (rare tho). Plug can simply be continuity-checked from electrode to connector.

You can test the points with a bulb and small battery wired across them to make a battery-bulb-switch circuit - bulb on = points closed, bulb off = points open (when the spark should happen, just at the point in the rotation that the bulb goes off, approximately).

I'd also get a new condenser (AKA capacitor or suppressor) before stripping it though, as getting the timing right afterwards is fussy enough without doing it twice. Why? It's unlikely, but if the condenser has failed (to now be short circuit), it will short the points so there can be no spark at the crucial moment. Condensers are pretty cheap, or should be, and the exact value matters far less than having the right mounting lug or whatever on it.


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## Chris152 (6 Sep 2018)

Thanks Eric. We tried the lead direct to the block but there was no spark, the lead continuity is fine and the coil seems to be ok, so we're going to clean contacts within the magneto asap. Hopefully that'll have it sorted, we'll see!


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## novocaine (7 Sep 2018)

You are doing well Chris, keep digging. I'm getting worried that it might be the flywheel that's the issue, lost it's magnetism over the years. might be worth waving a compass over it to see if it dances around. 

Eric, there isn't a condenser on the points, it's all to low of a voltage to charge a capacitor or make it worth while for protecting the points.


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## Eric The Viking (7 Sep 2018)

That sounds like a Very Nice Engine to work on then!


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## Chris152 (7 Sep 2018)

novocaine":u3stq32b said:


> Eric, there isn't a condenser on the points, it's all to low of a voltage to charge a capacitor or make it worth while for protecting the points.


Glad to hear that - I spent a little while finding out what a capacitor is, and then couldn't find any reference to it on the Seagull! 
We don't have a compass in the house - the boy uses his phone as a compass when we need one (I've no idea...), but I just held a file to the flywheel and it sticks well to one part of the wheel, so hopefully all good there.


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## novocaine (7 Sep 2018)

meh, 2 stroke, what you gonna do.  if you think about it, as a single cylinder engine thats only running at a few k rpm (it's screaming at 2k) there really isn't much stress on the points (in comparison to a 2 or 4 cylinder engine where they are possibly firing twice every revolution and much high revs) they last forever.  

they are quiet amusing little things to play with, so simply that if you can get a spark and fuel they will, unlike something a bit more modern that needs life support to work.

Chris, that's good news, how about sticking the drill on it again and testing for a spark while it's spinning? if it's got the original cap on it still (which I think it has) you can wingle out the end of the HT lead and do it without the spark plug if you feel the need. did you swap the LT wire to a new one yet? if not, do that now. then as you've already said, clean all the contacts and the big chunks of iron and give it another go.


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## Eric The Viking (7 Sep 2018)

After making a twit of myself* over the non-existent condenser, I hesitate to comment further, but... 

... in the past, I've found crimped fittings that are mechanically strong but that don't actually connect through the fitting to the wire itself, because the crimp was made badly. It's possible that the LT side was indeed originally made badly and has been iffy for years (only one or two strands actually connecting), but has now failed. 

Remaking the wires is probably a very good idea. The better those connections are, the stronger the spark will be on the HT side.

E.
*happens often.


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## novocaine (7 Sep 2018)

not made a twit yet Eric, if you haven't played with something this small you simply don't know stuff like that, every day is a learning day after all. Me, I'm used to playing with small things, especially things that need a lot of tugs to get going and only stop if you run them out of fuel.


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## Chris152 (8 Sep 2018)

WE'VE GOT A SPARK!

We re-cleaned the points, cleaned where the LT cable meets the coil (we couldn't replace it as it's soldered onto the points and have no iron), cleaned the contacts around the coil (though I don't think they actually contact anything?) and re-cleaned the connection between the HT lead and the plug - I don't think we did that properly first time. The sort of thing most of you'd have done in the first 10 mins I guess, but we got there!

OK, so now we move onto the fuel supply? It won't be today as he's gone out now - but I could get on with cleaning the inside of the petrol tank. It's alloy - do I just swill it out with some fuel?

Thank you!


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## novocaine (8 Sep 2018)

Excellent.

Swill out the tank. Fuel will be fine.

Change that fuel pipe then stick the scary end in water and see if it starts. If it doesnt then the carb can come off and be striped and cleaned. We can go in to that when we need to. 

Reckon if fuel flows it will start. Follow the starting procedure.


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## Chris152 (28 Sep 2018)

The boy's been away with his mother lots lately so work on this has been slow. BUT, we had a crack at the fuel system today (inset day in school):
https://vimeo.com/292332004
The oil mix was a bit hit and miss (the 2 stroke mixer bottle I bought this morning didn't have 10:1 marked on it, so we ended up putting 9cm depth petrol to 1cm oil in a jam jar). Lots of smoke which may be due to the mix, general dirt or maybe that's just the way it runs (I remember a trail of smoke wherever we went in the mirror with that motor!). 
Brilliant though, so happy with getting it going at last - that's over 40 years since it last ran!


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## novocaine (29 Sep 2018)

Superb. 

Now add the mud and we are ready to plaster.

Sounds good, 2 stroke will always smoke and you're close enough with your mix. 

Now to build a boat?


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## Chris152 (29 Sep 2018)

Ha, yes - we've been wondering how we're going to try it out! 
The plan is now just to remove the head and to look inside the gearbox, rather than strip the whole thing down - at least he'll get a good sense of how it works mechanically from that, the rest we can learn through diagrams/ videos. The danger with time constraints is that it never gets back together if we do a full dismantle as originally planned. But we'll definitely clean it up (more questions to follow on that...) and hopefully borrow a dinghy to get it on the water. 
We've both learned so much from getting this far, and _really_ appreciate the help everyone's given.


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## novocaine (1 Oct 2018)

There isn't a gearbox in there worth looking at, it's direct drive so just a crank (you'll have to split the casing to get a good look at that)
end of the day it cost you nowt, so if it never runs again it's no biggy, you've proven it works, he's learned some problem solving which is way more important than fine details here, now to get some us out of it for the young man and strip it, be careful on splitting the casing and you might save the gaskets. worst case you sell it for parts and keep some others running. 

once upon a time you'd go the scrappy and pull something apart, can't do that anymore, shame really. Have you thought about RC car's as a way to learn? you can pick up a burner for cheap enough. 

Isn't there an advert for the navy about this? something like if you can fix a skate board you can fix a bike, if you can fix a bike you can strip and rebuild a Turbomeca Makila 1a1 with your eyes closed, stood on your head with a silly hat on.


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## Chris152 (2 Oct 2018)

Ha, yes I've seen that ad but I don't think he has. Thing is, kids don't seem to sit and watch telly any more. They'll sit and watch a film on netflix with me sometimes, but broadcast tv doesn't even figure on their radars - youtube, subscription films and all that. But yes, that's the hope - he's built his own skateboard, obsessed with fiddling with and upgrading his bike, and now has got a small engine running. Next it'll be cars (_not_ motor bikes... :? ).

The problem with stripping the engine is that it's become sentimental now - that's the motor dad used to take us out fishing, pottering about on holiday and all that. Rather than potentially wreck it, I'm now thinking about getting a Mirror dingy to restore. Ones to restore seem to go pretty cheap this time of year and from what I can tell are pretty simple things? Plus that's wood, not metal. Point taken about the 'gearbox' - maybe just take off the head and have a look at the cylinder/ piston moving, then put it back together and get it looking nice.


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## novocaine (3 Oct 2018)

you get the plans for a mirror dirt cheap (any boat named after a news paper has to be cheap really), they are pretty simply to build yourself, you might find it a better prospect than buying a colander with a seat. have a search local for a mower repair shop, they usually have a couple of old dead motors laying about out back that if you explain your reasons they might let you have for nothing or not much, a bit more to them than the seagull and no biggy if you rip it apart to "learn". 
Saves the seagull and as it's got sentimental value now no reason to strip it further than you have. he can still learn a few more bits from it, like how to make aluminium shiny and what happens when you hit your old man in the face with a pull cord, both of which are essential life lessons.


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