hi all, my mate bought a greenfield ride on with a 11 hp gv 400 honda on it. it would not idle, hard to start and would backfire through the carby to the stage it has burnt the foam around the aircleaner element. After checking the fuel side of things, i thought things pointed to valve problems. I removed the head, but have not checked the clearances yet. What i found was on the intake stroke, naturaly the illet valve is open, but on the compression stroke you can put your thumb on the inlet valve and turn it all the way up on compression, the compression stroke has nearly hit TDC before the valve actually seats firm. on the exhaust stroke there seems too much over lap with the inlet opening well before the exhaust has closed. The inlet valve bit explains why its backfiring as the air fuel mix is escaping through the inlet manifold. Like i say i havn't checked the valve clearance yet, but it all seems too excessive. Can these engines run being a tooth out on the timing, as thats just what it seems like. I havn;t had much time and have to go to work again now but will look at it on the weekend. I think the way it looks we will have to go inside the engine, cause things just dont add up, thanks micka
