head bolt

[TRAV05]

I just noticed that one of my head cover bolts must of vibrated loose or something but now it wont tighten up, whats the easiest way to fix this problem, do i have to take the engine apart?

Thank you

[GPracer2500]

Remove the valve cover and repair the threads with a Heli-Coil kit. No dissasembly should be necessary beyond removing the valve cover.

Those 6mm bolts (8mm flanged head) are probably the most commonly mis-torqued bolts on the whole bike. 9 ft-lbs is the spec for those bolts. The OEM manual specifies 20 ft-lbs for the "cylinder head cover bolt (8mm)" but that is the one larger bolt in the center of the valve cover--NOT all the other smaller bolts. The "8mm" refers to the thread size, not the socket size. The smaller bolts are 6mm (with an 8mm head)--kinda confusing...

A good 1/4 drive torque wrench is the best tool for that job. Many 3/4 drive torque wrenches aren't very accurate in those low ranges and many don't even adjust down that far. Sometimes going by feel is best....

Be sure to re-check your valve clearences after removing the valve cover.

Good luck!

[NacsMXer]

Originally posted by GPracer2500
Remove the valve cover and repair the threads with a Heli-Coil kit. No dissasembly should be necessary beyond removing the valve cover.

Those 6mm bolts (8mm flanged head) are probably the most commonly mis-torqued bolts on the whole bike. 9 ft-lbs is the spec for those bolts. The OEM manual specifies 20 ft-lbs for the "cylinder head cover bolt (8mm)" but that is the one larger bolt in the center of the valve cover--NOT all the other smaller bolts. The "8mm" refers to the thread size, not the socket size. The smaller bolts are 6mm (with an 8mm head)--kinda confusing...

A good 1/4 drive torque wrench is the best tool for that job. Many 3/4 drive torque wrenches aren't very accurate in those low ranges and many don't even adjust down that far. Sometimes going by feel is best....

Be sure to re-check your valve clearences after removing the valve cover.

Good luck!

This is true... I made that same mistake you said above by torquing the valve cover bolts to 17 ft lbs as specified in the manual. Guess I didn't read it closely enough because that was enough to snap the first bolt I torqued to that spec :eek:

Going by "feel" is definitely a good way to go when tightening the valve cover bolts. I use a small 1/4 inch drive ratchet and choke up on the handle to simply "cinch" down the bolts. Even a 3/8 drive ratchet would give a misleading feel because those bolts are so small..:ermm:

[GPracer2500]

Originally posted by NacsMXer
...I use a small 1/4 inch drive ratchet and choke up on the handle to simply "cinch" down the bolts. Even a 3/8 drive ratchet would give a misleading feel because those bolts are so small..:ermm:

That's a great tip--I do the same. I don't usually switch over to a 3/8 ratched until I'm working with a 12+ mm socket. Even then, I'll sometimes stick with 1/4 drive until I need 3/8 drive tools.

Regarding the torque of that center bolt: my 99-02 OEM manual lists 17 ft-lbs on the torque spec page in the the "General Info" section but then lists 20 ft-lbs for that same bolt in the "Cylinder Head/ Valve" section. One of em' is a misprint, I guess?? :ermm: