jorden1979

At an idle I heard a ping/metal on metal sound. When I ride sled i can feel it pulling itself then lets go and pulls again over and over etc..I have ruled out the clutch cause I took the top half of the engine apart and went through it good and found the top of left cylinder was hitting the head it seemed. On the head its seems as though hair line fractures have appeared. What causes that to happen and what should I do and what parts should I replace to get it back running again...

kccats

Is the piston all damaged? It's hard to imagen the piston actually hitting! There could be little pit marks from preignition?
Remove the pistons and look at the wrist pins?

jorden1979

I removed the pins and they looked good but the top of the piston on left side is got some good dings and the cylinder head has some pretty good ones also. On the flipside of the cylinder head are stress cracks. I ordered a new top end kit and a new head. everything i need to rebuild top of motor. Any tips, How do I clean inside the crank case properly

kccats

You should also get new needle bearings. I usually just spray WD40 and a paper towel.

jorden1979

i finally got the piston kit, spme cleaner and im assemblying the engine now.....Any tip on installing these pistons.....and what way should these gasket face, with the print on them out or in?