Hi, Jim, I have read this 2 page post ( while having a beer ) and see that you have not checked the valve clearances yet. Tight valve settings will cause the problems you are having, also the valves may be sticking when hot. One test that you could do is a compression test cold , then run the motor till it will not start and then do another compression check. If it is a lot lower you have a valve problem. Factory settings are, IN .006-.008 set when motor has been driven for at least 30 min., EX .013-.015 set at the same time. For cold settings, start at about .015 IN and .020 EX, then drive 30 min.,reset valve clearances to hot settings. Remember everyone, a motor needs 3 things to run, Spark, Compresion, Fuel. And last but not least Have Fun. Brian
