2 stroke garden machinery frustration

[John Brown]

Any 2 stroke experts on here?
I stupidly bought a 2 stroke wheeled strimmer on FB marketplace, for the princely sum of £29. The vendor, who I now suspect to be an accomplished fibber(there are missing bits and pieces and stuff that I can't be bothered to go into), said it had been in his barn for a couple of years, ran fine last time he used it etc.
I got it running with a bit of carb cleaner and Bradex, but it ran like a pig, only with choke, and enough white smoke for several pope decisions. New carb and fuel pipe/filter from Amazon, still the same. I'm slightly perplexed, there are only two adjustments, the main jet and the idle stop screw...
It starts and runs, after a fashion, but is totally unusable.
Any ideas?

 

[Stigmorgan]

Pretty sure white smoke could be a sign of water/oil mix. If it's been sat for an extended period then condensation would have built up causing water to mix with the oil and fuel, have you drained and cleaned the whole thing completely?

 

[Spectric]

What is the make and model as that may help. Two stroke horticultural machinery is very simple but can drive you insane when it goes wrong, carburation often being a culprit but you say a new carb has been fitted. First thing to look at is the fuel, have you drained the tank and filled with a fresh two stroke mix of the correct oil to fuel ratio ? If it has been sitting with E10 in it then that can ruin the carb, use Aspen or find some E5 .

Fit a new spark plug so you know that is ok, they do gum up in two strokes so worth changing. Did the carb come with a new air filter ?

After these basic checks does it have compression or just easy to spin it over ? If you are still drawing a blank then maybe time to take it to your local repair centre.

 

[Tris]

To add to Spectric's answer, after new spark plug and compression check, then clean up the flywheel and 'contacts' of the ignition module. Set the gap and check for a good spark.
If you've got that, and with a new carb fitted, then white smoke will either be too much oil in the mix or too little air in the mix. If it's running, even roughly, with choke on I'd try draining it out and trying a 25:1 mix with good quality oil

Good luck, I know how annoying these engines can be

 

[John Brown]

Fuel: I've taken the tank off, cleaned it out with IPA, added fresh fuel.

 

[John Brown]

What is the make and model as that may help. Two stroke horticultural machinery is very simple but can drive you insane when it goes wrong, carburation often being a culprit but you say a new carb has been fitted. First thing to look at is the fuel, have you drained the tank and filled with a fresh two stroke mix of the correct oil to fuel ratio ? If it has been sitting with E10 in it then that can ruin the carb, use Aspen or find some E5 .

Fit a new spark plug so you know that is ok, they do gum up in two strokes so worth changing. Did the carb come with a new air filter ?

After these basic checks does it have compression or just easy to spin it over ? If you are still drawing a blank then maybe time to take it to your local repair centre.

We buy E5 for mower, Stihl strimmer, Stihl leaf blower. Oil is Stihl branded. I have fitted a brand new carb.
There is a spark, as it does run, just not in a useable fashion.

 

[Spectric]

There is a spark, as it does run, just not in a useable fashion.

You may have a spark but the plug could be breaking down under cylinder pressure which you won't be seeing. I have had a lot of two stroke motorcycles and always carried a spare and plug spanner !

 

[RogerS]

Not a Husqvarna by any chance ?

 

[Spectric]

Not a Husqvarna by any chance ?

Just had my Husqvarna hedge trimmer repaired and serviced, that started and idled fine but would not rev and it was a carb diaphragm had gone.

Yet I have a very old Allen strimmer, at least thirty five plus years old with a Kawsaki two stroke engine and it always starts and runs just noisy and smoky.

 

[John Brown]

Not a Husqvarna by any chance ?

No. My neighbour has a 5.5k Husqvarna robot mower,but that's approaching car pricing for me...
Not sure of the manufacturer, the strimmer is branded Hornet, but the engine appears to be a ubitiquous 52cc 2 stroke, used in a multitude of devices.

Compression feels OK. Can a bad plug cause bad running and smoking?

I could take it to the local garden machinery place for a service, but it seems like the thing is only 160ish new, so probably not worth it, my time is worth very little these days, which is why I get into these situations!

 

[Fergie 307]

Heavy smoking and only running on choke sounds to me like too much oil in the mixture. If you are using the stihl oil then it is synthetic high quality stuff and you need a lot less of it, something like 50:1, if I remember correctly, it should tell you on the bottle. If you go by what it says on the machine, often on the petrol cap, and use it at maybe 20:1, you will get exactly what you describe. Changing the plug is a good idea, they do break down eventually.

 

[Superduner]

Is the 2 stroke mix correct? Some machines use 40:1 and some use 25:1. Maybe Google can help you find the correct mix?

Edited to say that Fergie and I posted more or less the same thing at the same time..........

 

[Tris]

Just had my Husqvarna hedge trimmer repaired and serviced, that started and idled fine but would not rev and it was a carb diaphragm had gone.

Yet I have a very old strimmer, at least thirty five plus years old with a Kawsaki two stroke engine and it always starts and runs just noisy and smoky.

A tree surgeon friend often says if you like tinkering with engines buy a husqvarna, if you like earning buy a Stihl.

We have a husqvarna rotavator at work and this season it started cutting out as soon as it got warmed up, that turned out to be a bad plug. There was still a spark when cold but I guess the insulation must have cracked and once hot it could short somehow

 

[Henniep]

Idle but won't rev - runs rough = all of the aforementioned, but very possibly a silencer clogged with carbon. Too much oil in the fuel mix, faulty spark or other poor ignition will deposit gunk in the silencer which interupts the free flow of exhaust air. Remove, clean thoroughly and reassemble.

 

[pe2dave]

Try youtube for setting the mix / idle on the carb?
With the carb removed you should be able to see the piston (use a torch).
Is the piston pitted at all? I bought a new piston / head for £60, fitted in a couple of hours.
Good luck.
As above, could be the timing gizmo rel to the flywheel magnet?

 

[clogs]

when u get it running just use the top grade fuel without ethenol and ONLY Synthetic oil......
when fishished using the machine tip the fuel out of the tank back into a storage vessel....
then start it until it runs out of fuel....
that way there's no gumming up or water getting into the fuel/carb/tank...........
The cheapo fuel with the addative actually attracts moisture.....
Plus it eats fuel lines/pipes...even alloy.....
Nothing wrong with the cheapo carbs from ebay........
often an ultrasonic dip wont clean em so a new carb is needed.....
loads of good info on u tube....*Taryl fixes all* and others.......
PS. my regular proff chainsaw died in the middle of the job and had to order parts......
was paying somebody to help, so now costing me money.......
bought a chainsaw from Lidil......never been a moments trouble....
starts first time everytime.....only prob it's to big for me to handle.....arthritis.....

 

[Ollie78]

My Strimmer was idling but would not run once you openned the throttle, the issue was the carb was just not supplying enough fuel at all. I had to buy a wierd shaped screwdriver from ebay, I turned the jet way up and its fine ever since.

Ollie

 

[Chris Harris]

You are sure about the mixture aren't you? I gave a strimmer to my son. After a few weeks we were talking on the phone. He said it started and ran but lots of smoke and a bit slow. He was putting 20 parts of oil to 1 of petrol!. How it started I don't know, but it's fine now.

 

[Myfordman]

Maybe youtube contributor chickanic could help. There is not much she does not know about small machinery engines.

 

[John Brown]

Thanks all. Lot to think about there...
Mixture is roughly the same as I use in the Still strimmer and leaf blower, and E5.
I might just sell it on to someone who knows what they're doing(I thought I did, but beginning to have doubts). I only bought it because it was cheap and local, and at this rate it'll end up costing me more than a new one.
Really on the lookout for a cheap 4 stroke Honda strimmer, I use one at the local churchyard now and then, and it's a fantastic piece of kit.
I miss our sheep, they did a pretty good job, but the rest of the family aren't keen on replacing them!