Hot Cams dont seem to fit.

23 replies to this topic
  • grayracer513

Posted May 01, 2005 - 01:18 PM


A bolt that is lubricated with grease or a anti-seize compound creates less friction than a non-lubricated bolt. So, with the same amount of force, the lubricated bolt will obviously turn further than the non.

The lubricated bolt will turn approx. the same amount of distance as the non-lubricated bolt by using only ~80% of the force needed to turn the non-lubricated bolt that distance.

I picked this info up at a Diesel Trade school I went to many years ago. Your torque coefficients change when any lubricants are applied, also you can run into a hydraulic lock state. Our factory manual show most fasteners are dry assembled, unless otherwise noted.

Except for one thing: the YZF service manual specifies that the bolts are to be lubed with engine oil, then tightened to the torque values given.

The torque values themselves have been reduced in recent manuals, and Tryce and I agree that the original figure seems high at 7.2 ft/lb (86.4 in/lb). I have used 70-75 in/lb since the first time I adjusted the valves on one of these bikes. Tdub uses 60 in/lb, which as I understand it, is what the '05 manual calls for.

In the manual there is a procedure to check the cam clearance in the saddles. I would look into that, or follow tdub's advice.

  • sirthumpalot

Posted May 01, 2005 - 02:35 PM


....Our factory manual show most fasteners are dry assembled, unless otherwise noted. ....

This must be the difference. I've always been taught to install lubed bolts/nuts and that the torque specs are given assuming lubed nuts/bolts. First chase with a tap/die, then lube, then install; otherwise you really have no way to get a consistent torque reading.

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  • yzf450jack

Posted May 01, 2005 - 06:30 PM


Your shims might be to thick try taking out the buckets and see how it spins It could be pushing on a valve and The caps that hold down the cam are align bored so you can't interchange them like rod caps on a car I don't remember if it was like that on yamaha cam's

  • Slowmotion426

Posted May 01, 2005 - 07:44 PM


When you took them off did you loosen them in a criss-cross manner...if not it's possible to warp them...

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