Questioni have acraftsman 10 hp riding lawn mower. when it is shut off and it is in the upstroke and i go to start it, it will not turn over. when i turn it by hand and get past top dead center it will turn over fine. i was told a double head gasket would take care of the problem. is this true? i was also told that the lash valve has to be reset. what is and where is this valve located? is it a simple adjustment? help? my machines model #is 502.255030. the engine model # is143.436012 and the year is 1994.
AnswerI've never heard of double head gaskets, but it would definitely lower the compresison ratio.
Have you checked or replaced the battery or battery cables lately? We had a Snapper do the same thing once, and we replaced cables and ran a new, heavier wire for the solenoid exciter. Worked great.
As for the valves, I would check them but normally the valve have more of a tendancy to stretch, decreasing the valve tappet clearance and lowering the compression. Both valve are set to .008 inch at TDC on the compression stroke.
What is the cold cranking amps on the battery?
Just for good measure, check the the head bolt torque...200 inch pounds. Tecumseh engines are prone to vibrating headbolts loose, causing all sorts of weird problems.
Let me know about the battery and cables.
Eric
