I'm working on a Husqvarna 128ld string trimmer and I have put 3 different carburetors on it but can't get it to stay running. I've tried removing the muffler thinking maybe it was stopped up but still no success. Has anyone run across this before? Any replies would be greatly appreciated.
There is methodical method to small hand held 2 stroke engines .
You start with the fuel tank checking that the tank both holds pressure ≈ 7psi for 2 minutes
Then you check the cap to see if it vents properly
Faulty tank caps & vents are much more of a problem than faulty carburettors
But it would be really helpful if you described your exact problems because if the tank does not vent it can cause the engine to stall rich or stall lean
Rich is when the tank over pressurises and lean is when it does not allow air to get in .
Then there is the impulse line / hole if that leaks then the pump can not work
And of course you could also have a hot short in your coil or a chaffed ground wire
If you loosen the cap slightly will it run for longer
And of course there is the perpetual problem with vendors buying defective carbs as scrap metal then flogging them off on line using descriptions like "fits a " or "OEM for " but no hwere in the add does it says the carb actually works.
You would not be the first person who has bought a handfull of trash carbs .
#3
StarTech
Or it could just be worn out or straight gassed.
I got a Stihl FS70 here that was straight gassed. It will start, run poorly at full throttle, but won't idle. Compression just too low for it work properly. Pulled the muffler and the piston and cylinder looks terrible. Just calling it and returning to customer so he can buy a new one.
When it comes the carbs here lately I have been a lot needle seats leaking between the carb body and seat.
