Thread: Chainsaw question - engine dies

Nice and soft might be just as bad as hard if it is the diaphragm pump type. The diaphragm plate should be perfectly flat so it seals, if it isn't it won't work...

Now to be devils advocate here, I have a cheap 2 stroke generator here that I've been blaming the carby on. Would start and fire right up, stagger for about 10-15 seconds then cark it. I did every check I could think of, including replacing the carb which didn't change a thing. Then I spied the compression tester and hooked that up - only pulling 50psi max. Hmmm...

Taking the thing apart (it is effectively brand new but died after around 5 minutes of running and the owner just chucked it back in the box about 7 years ago leaving the fuel in it) the piston rings have a tiny roll pin that stops them spinning, one of the pins had backed out and dragged a score mark down the bore below the transfer port. So that's something to check - compression and vacuum testing the thing to make sure it's not a mechanical failure before you start replacing parts randomly chasing something that seems like the cause but isn't (like I just did haha).