Hi Everybody,
So I've been reading as many posts as I can about Vac and Pressure testing, and I still have a few questions. But first, here is why I am testing this saw. My 346xp (1998 model, orange cover) was killed by a coworker...it had good compression when it left the shop, and the carb was tuned using a tach. They say that after a few minutes of running full bore with no load, shaving a spring pole (I know, I know) that it over heated, stalled, and wouldnt restart. He brought it back and the piston was fried on the muffler side, no compression to speak of.
Now I covered the intake, between manifold and cylinder, and exhaust between the metal muffler ?gasket? and cylinder, with rubber bike tube material, and bolted everything back together. Replaced spark plug, too. With my mityvac hooked to the impulse hose, I couldnt get any reading on vac...could this be due to a bad piston? I though that wouldnt matter. Any other ideas? Is it just a major leak I never knew of?
I'm considering rebuilding it, I got it for free, so it's still worth it to me, even at the price of a 346 p/c, just not if I can't find the original problem. Is it likely that a bad seal in the crankcase caused problems that were temporarily covered when I tuned the carb, which then got worse when they ran the saw later? Can a crankcase be tested without a cylinder bolted to it?
Thanks for all the great info on this site!!!
So I've been reading as many posts as I can about Vac and Pressure testing, and I still have a few questions. But first, here is why I am testing this saw. My 346xp (1998 model, orange cover) was killed by a coworker...it had good compression when it left the shop, and the carb was tuned using a tach. They say that after a few minutes of running full bore with no load, shaving a spring pole (I know, I know) that it over heated, stalled, and wouldnt restart. He brought it back and the piston was fried on the muffler side, no compression to speak of.
Now I covered the intake, between manifold and cylinder, and exhaust between the metal muffler ?gasket? and cylinder, with rubber bike tube material, and bolted everything back together. Replaced spark plug, too. With my mityvac hooked to the impulse hose, I couldnt get any reading on vac...could this be due to a bad piston? I though that wouldnt matter. Any other ideas? Is it just a major leak I never knew of?
I'm considering rebuilding it, I got it for free, so it's still worth it to me, even at the price of a 346 p/c, just not if I can't find the original problem. Is it likely that a bad seal in the crankcase caused problems that were temporarily covered when I tuned the carb, which then got worse when they ran the saw later? Can a crankcase be tested without a cylinder bolted to it?
Thanks for all the great info on this site!!!