7.2 ft-lbs (86 in-lb) too much torque for cam cap bolts?
Posted September 21, 2004 - 08:14 PM
Posted September 21, 2004 - 08:40 PM
Something else is wrong. Use a micrometer to measure the diameter of the cam journals and see if they are the same. When you torque the caps they shouldn't pinch the cam. If they do and you just don't tighten the caps fully it will still screw up the cams and your head.
Posted September 21, 2004 - 08:46 PM
Posted September 21, 2004 - 10:10 PM
Posted September 21, 2004 - 10:32 PM
Posted September 28, 2004 - 07:07 PM
Posted September 28, 2004 - 07:15 PM
Posted September 28, 2004 - 07:20 PM
Posted September 29, 2004 - 01:01 AM
since it was the first time I did that, I was working step by step, checking all possible things
when I removed both cams, I tried to remove the lifters (out of curiosity), but the inlet ones were stuck due to the damaged cam seats on the head (at that point I really thought i need a special tool for removing those)
removed the head, peeled and brushed off (PIC) the defective material, polished the cam seats on the head and on the camshaft cap to even the surfaces with 1000 sandpaper, slowly, and checking often
before i began sanding, the cam could not rotate by the force of hand, and after the job was done, it rotated smoothly as the exaust one, when torqued to the spec
I fixed it myself , since then I checked it twice for deformities, and it all looked OK, valve clearances solid
(never trust your yamaha to a husqvarna mechanic)
proof more that a yamaha HQ and hi-tech bike can be repaired with tools for everyday use, only cost was new head gasket and time spent for repairs
Posted September 29, 2004 - 07:08 PM
Try turning the cam with the cam chain off to see if it has a loose spot. The cams are hollow and you may have gotten a bent one.
Since I live in the middle of nowhere with no bike shops or parts and I was still in a big hurry to go riding I very gently sanded inside the caps until the cam would rotate freely. It didn't take much, only a few swipes. It may blow up tomorrow but it lasted 2 years so far.