Should Cams turn?

[YFZer]

When you got the timing chain off and head off, should you be able to turn the cams by hand a little bit back and forth before the lobe hits the valve. My cams are really hard to turn, should they be like this?

[jshtex]

The intake cam should rotate freely untill the lobes come into contact with the shim buckets.

The exhaust cam will rotate between the lobe contacting the bucket and the decompressor pin contacting the bucket.

But to answer your question, yes, they should spin some.

If they dont you should check your valve lash and look at the bearing surface in the cam towers and the head for problems.

[GPracer2500]

Make sure the cam tower bolts are torqued correctly.

[rpyfz450]

They should not be snug. If they are, do not reassemble and llow them to be snug. The book also calls for moly lube of many of the top end parts.