400ex rocker bolts not holding

[undergroundart]

so I ve had a small oil leak from around the head on my 99 440ex. quad runs great so I have nt been too concerned but I finaly had time to take the tank off to get a better look and notice 2 rocker bolts are missing and over half of the bolts that are there dont catch any of the threads. I have replacement bolts and comparing my replacements with the ones in the engine looks like my bolts didn't break off. like maybe the previous owner stripped out the threads. is there anyway to fix this? really hoping I dont need a new cylinder

[DragonGunner]

so I ve had a small oil leak from around the head on my 99 440ex. quad runs great so I have nt been too concerned but I finaly had time to take the tank off to get a better look and notice 2 rocker bolts are missing and over half of the bolts that are there dont catch any of the threads. I have replacement bolts and comparing my replacements with the ones in the engine looks like my bolts didn't break off. like maybe the previous owner stripped out the threads. is there anyway to fix this? really hoping I dont need a new cylinder


So the bolts in question are the ones holding your valve cover on up top to the head...? If so you can have some one tap and thread for bigger bolts or put threaded sleeves in. This has nothing to do with the cylinder. The cylinder has 4 bolts that come up through the head and have nuts on them holding the head on.

[CJM]

Been there done that with a friends. We went to 7mm and still had issues. he wound up getting a new head an rocker cover in the end. COuld try and helicoil them but that would make the holes even larger.

Id suggest if the threads arent to bad to try tapping to 1/4" SAE as its SLIGHTLY larger than the 6mm threads. But that will only work if the threads arent to bad already.

[450rtt]

helicoil will be just fine. those bolts don't torque much at all ya just need a little more bite.