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Hello everyone, I have a problem that's making me nervous.It's a kz1000 A1. The cylinder head was repaired, new stainless steel guides and valves were added, and the camshaft bearings were also changed.On the first start, the engine stopped running immediately, and upon disassembly, some bearings were found to have stuck to the camshaft.I thought maybe I didn't lubricate it enough after multiple starts.On the second attempt, I used some of the old bearings and some new ones, making sure to apply grease from the first assembly and plenty of oil to the bearings.After 5 starts and the engine running for 3 seconds, it suddenly stopped. Upon disassembly, one of the new bearings on the exhaust camshaft had stuck and turned.Has anyone had problems with new camshaft bearings?Thank you.

Are you sure you have the cam caps in their right places and not backwards? Is the head flat? The bearing clearance is .001-.006. On the head I'm running now I had to use cam caps that didn't come with it as the others were missing. Two I got to fit facing forward but two wouldn't work unless I installed them backwards. They are line bored with the head so they only fit one way. Even then I had to hone them to get the proper clearances using a plasti gauge. Pics?
Steve 

Stainless valves yes but never hear about stainless steel guides. You have to remove the head, valves and springs. Now you have to find the matching cam caps clearance (plastigauge) by installing only the cams and new cam bearings so the cams are spinning free. If anyone anyhow mixed up your cam caps in the workshop from a different head you will have a big problem.

I expressed myself wrong, the guides are bronze, the cam covers are correct.

The bike was running before disassembly, the cam covers look in the right place.
What changed was that the threads of the cam covers were repaired with helicoil, with a tightening of 1.2 kilos.

A pic of the cam caps?

There is a member here going through the same issue using new cam bearings. No help to fix but your not alone.

www.kzrider.com/forum/11-projects/616295-1973-z1-maui

I already disarmed but I send you in the order they were. 

Hello thank you very much. I bought the cam bearings from z1 Enterprises.

I'd like to see the bearing surfaces and the numbers on the back. Using a plastigauge will tell the story.
Steve

I've heard of issues with pattern cam shells but never had a problem myself.
It's possible the actual bearing material is inferior and not up to the job.
If you have your originals and they aren't worn through to the steel backing it's best to re use those.
The shells in the cap get more wear due to the upward valve spring pressure so put the best looking ones there.


 

I had put the old bearings back in, except for the new one that failed, I'm going to have to buy plastigauge