tecumseh lh318sa low power questions
ok my brother dropped of his snowblower the polan pro model with the 8.5 hp flat head engine. he complained that when he is getting into snow the engine slows down and will not throw the snow like it did a few years ago. he took it to a service shop and they put new belts on it and then told him it has low compression
so i did the compression dry was 30psi wet was 35psi oil on the valves was 35psi using the rope.
so i did my craftsman with the same engine and it had 35psi dry
so i did my poland pro with the ohv engine and it was 50psi dry
so i tore his engine down today and found the exhaust valve opens for the decomp like it should but i noticed the valve wobbles as it moves up and down. and it kind of looks like it is not fully seating. that could be a big issue so i will re-gring the valves and lap them. but i would like to change the guide but can't find it in the parts listings. can the guides be replaced?
also i took the piston out and the bore looks great no scoring so i took the rings off the piston and using the piston to push each one down the bore to the wrist pin i got top ring .020 center .024 and oil ring .035 the piston is 3.09 dia. the bore is 3.12 dia.
the intake valve is clean the exhaust is oily and has its share of crude on it as you might expect. the rings do not look to be scored and of course not broken yet.
so now i have to get the valves out just learned how to do that and then grind them and lap them but it may be pointless if the guide is worn bad. i get about 1/16" side movement. and i wonder if when it is closing it is not seating enough to seal and that is the low power he is getting. also when i looked into the bore thru the plug it did look like the exhaust had dirt on the seat compared to the intake.