Home Forums Tech Talk What did I do wrong? Reply To: What did I do wrong?


Pete Schaible

The plug looked nice and gray.  Slight leak of oil between exhaust and cylinder but not much.  I had pulled apart the carb and all passages were clean.  I am suspecting either a vacuum leak at one of the seals or a coolant leak at the head dripping onto the piston.  I should have replaced the piston and ring earlier and I am learning the false economy of stretching the time on replacing them.  If anything the engine smoked a little less than usual.  I did drop the needle half a groove but the outside temperature was hotter than usual.  I don’t think it was a lean stick due to the carb settings…. maybe elsewhere but not the carb.  Motor temp was up to about 170, radiator temp 150.  Above ideal but I didn’t think dangerously high, and that was in grid before actually starting my run.  Could an old piston fail in this way or did I kill it?

The one thing I did notice is that when I would spin the wheel to start the motor it felt… rougher…. Like not enough oil.  I was running the same ratio as always, a different brand, but I don’t really believe that the brand would make that significant of a difference.  At the previous event there was just the slightest hint of a stumble when snapping open the throttle.  So I think it was a problem that got worse quickly but progressively.