My daughter has a 2002 50cc dinli ATV. It keeps blowing head gasskets. I have checked the deck surface and cylinder head for warpage and there doesn't appear to be any. I am at a loss. Is it possible the bike is running to lean. It had oil injection system but have since gone to a 32:1 premix. Any help would be greatly appreciated.

 

are you torquing the bolts after a gasket change out?

 

I torqued the head bolts to 12 lbs/ft. But they were a lot tighter than that when I removed them the first time. Is it possible that the threads have pulled and are not letting the head tighten down enough?

 

after you replace the gasket, torque the head bolts down to specs. Then run it and let it heat up and cool down then retorque....sometimes when it expands and contract it can loosen the tourque...if that makes sense....whenever I rebuild an engine I always retorque after I run it and get it up to temp.....