Motor bike, again.

[Digit]

The rebuild of this machine proceeds apace, (slowly!), many parts are now unobtainable, so far I have had to make 44 parts myself, but now I'm beaten.
To those not in the know the carbs on Jap bikes are attached to the cylinder heads via a moulded rubber tube, and on this machine they are scrap, and unobtainable.
So back to the drawing board. The carb inlet stubs are 38mm inch and half in diameter, so hose of a suitable bore will substitute nicely, but it has to be petrol reistant, which would seem to mean Nitrile.
I've tried E-Bay and Googled without success. Can anyone help me get this ***** bike roadworthy?

Roy.

 

[Tusses]

do you weld ?

how about making up an inlet manifold out of steel tube and curves ?

 

[Digit]

do you weld ?

Yep! But bike carb systems are nothing like car ones T.
One carb per cylinder is the norm with a short rubber connecting tube between. Where car inlet manifolds are often heated bike ones are insulated from the engine heat by the rubber tube.
Car heater hose is a perfect fit, but not resistant to modern fuels, unfortunately.
Hence my problem.

Roy.

 

[Tusses]

I've had a few jap bikes ... kwaks mostly

How about steel and exhaust wrap ?

 

[Digit]

These parts are about one inch long with two 'Jubilee' type clips around them, one clamps the rubber to the carb and the other clamps the rubber to the inlet stub on the head.
There is simply insufficient room for any thing else.
This engine is a Vee twin with the carbs in the Vee, and so tight is the fit to the frame that the exhaust sytem, for example, can only be fitted to the engine out of the frame!

http://www.google.co.uk/imgres?imgurl=h ... A&dur=1277

It's a nightmare.

Roy.

 

[Tusses]

ah, I was going to ask which bike it was, next !

I presume youv'e checked to see if the same part is used on other bikes ?

Rich

 

[DaveyP]

Short section of radiator hose... ?

If what's available isn't petrol resistant enough, then there are quite a few companys that make hoses to order that will be of the better material, just tell them what you want.

However .. I'm kinda convinced that there will be genuine parts from another bike that will do the job, but you have to find the right mechanic / parts person to know the answer.

 

[Digit]

That would be the ideal way out Rich, but not even David Silver is prepared to walk around their stores and find out.
If the stubs hadn't been butchered I could soften them, but they really are a bit past it. A previous owner put his faith in Silicone, lots of it!
I've already had to make dowels, bolts, O rings, spacers, caliper pistons etc.
It's now becoming a challenge!

Roy.

 

[Digit]

My nearest parts supplier Dave is 36 miles away! It's 22 mile round trip for an MOT, it's biking desert round here mate!
The only other biker I know of around here is my son!
I approached the nearest supplier for some parts some time ago, I chose middle of the week so as not to cause problems, all I wanted was standard stuff, tubular dowels.
They wouldn't even look in the stores!

Roy.

 

[DaveyP]

My nearest parts supplier Dave is 36 miles away!

Nope ..don't think local Roy

Every supplier in the UK / EU.. or even in the whole wide world is as near as your PC keyboard, lol

There are loads of folks who want your money and are just waiting for you to get in touch. The postage costs
a darn sight less than the petrol going on the round trip to collect them.

 

[merlin]

Hello Roy,
I had a Triumph T160 a few years ago and I fitted bank of Z1000 ST Mikuni carbs on it, I used some short lengths of radiator type hose and hose clips (the same as Triumph used) and never had any poroblems.
If you measure the o/d of your carb inlet I could see if they would suit yours?
Cheers,Merlin.

 

[Digit]

Yep! Trouble is I can't find 'em!
I've Googled Nitrile tubes/hoses etc, I've been on E-bay for the same as well as Honda parts and drawn a blank all round.
According to David Silver/Wemoto they simply aren't available.
Other parts are available, if not for the VT, then for other models and will fit, but inlet stubs, no way!

Roy.

 

[Digit]

I've checked rad hoses merlin and they are an ideal fit, but swell when exposed to modern fuels.
Having said that, the actual exposure in use would be about 3 mil of the internal length, so my fall back position is rad hose and smear the interior with silicone and see what happens.
It's rather unusual to find such a dearth of bikers as round here. I'm 71, today as it happens, and when I walk into a bike shop at any time I attract very some odd looks.
On one occasion I was greeted with laughter when I took my helmet off.
'You don't ride a bike? At your age?' is the politer comment.

Roy.

 

[Tusses]

many happy returns

Have you tried the breakers ?

It's been a while, but I have some old contacts in the business, if you dont come up with anything, I'll see who's still about.

Rich

 

[Digit]

I have indeed, it was a rare bike when new of course. I've even looked up spares for the VF400 which is identical, more or less, but again the rubber parts are off the list.
If anybody had illustrations I'd look for similar and ask for dimensions, but no luck there either.

Roy.

 

[t8hants]

There is a similar part on the carb' of a Honda CB 250 RS. I don't know if it the correct size without taking mine to bits, which I have just finished rebuilding. Try looking at the parts diagramme on this site and see if looks usable. http://www.cmsnl.com/honda-cb250rs-a-1980-switzerland_model16360/partslist There are lots of RS's about.

Gareth

 

[MickCheese]

Roy

I have just checked the inlet rubbers for my NC30.

They have, at a rough measure with a ruler, a 38mm internal diameter on one side but a small diameter, about 32mm on the other. Are you sure your inlet stub is the same diameter as the carb stub? If it is any help I can measure mine more accurately.

As for breakers don't even bother, they will be hard and perished.

Mick

 

[Digit]

Gareth, 250RS, a lovely lightweight machine. I've had three, the last one I fitted with the 500FT engine. Wish I'd kept it now but the local police took an inordinate interest in it as they couldn't identify the model as i flashed past!
Only time I've been nicked for speeding!
Can't tell if the stub is the same from the pics but will investigate further.
Mick, you caught me out on that one mate, I assumed that the dimendion was the same at each end, but it's not.
The carbs are 38 mil and the engine is 35 mil!
Late yesterday evening I found that silicone is not fuel proof, so that idea died and then I located a company, danST engineering, that does specialised silicone fuel hose but only in a 40 + mil so I'm also gonna E-Mail them.
But the wife's shouting she's ready to go shopping now! They haven't a clue have they? :lol:

Roy.

 

[Blister]

What make, model and year is your bike ?
.

 

[MickCheese]

Roy

If it helps I have an old NC30 one sitting on my desk that I have replaced and got the measurements from. I am sure they are still available from David Silvers. If you want me to send it to you so you can check the size or see if it can be modified to fit then PM me your address and I will pop it in the post.

In fact I can probably find all four if any use to you. They are fuel tight but lost some of their elasticity and on a V four that means you cannot get the carbs on and off so I changed them.

Mick