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82 xs400 Valve / Camchain Timing question

Posted: Tue Aug 07, 2007 2:16 am
by MrShake
Hello folks!!

I'm getting SO CLOSE to having a running bike that I can taste it, but I was delt a blow last night, and I'm stuck. Heres the deal:

I had to rebuild the top end of the engine due to, what I believe was, a badly torqued valve cam sproket bolt. It broke the chain and bent a valve. So, I have torn the engine down to the crank case, got out the offending bolt, got a new chain, new valve, lapped the valves an seats, etc, etc, etc.

Now, I am at the step of putting the cams back in and setting their timing before reinstalling the engine. I gave it a try last night and it doesn't make sense to me, I'm hoping someone has some experience to share with me.

The XS400 has timing marks on the cam caps and then on the "face" of the cam shaft itself. With the engine at TDC on the left cylinder (per the service manual) I lined up the marks and went to put the caps on.

The first problem (maybe not a problem, but it seems odd) was that the intake cap, with the marks lined up, had one of the lobes pushing down on a valve lifter. It seemed to me like an odd thing to be tightening the cam down while contacting the lifter.

The 2nd problem, the service manual is confusing. It talks about lining up the marks on the caps, and then the marks on the "face", and I'm unsure what the "face" it refers to is, I originally assumed that it meant the dot/mark on the outside of the end of the shaft (facing up). It seems to get harder to read from there.

I took a break last night and will review the manual again tonight in hopes that I missed something, but I'm hoping someone has some insight on setting the valve/cam timing on this bike!

Posted: Sat Sep 01, 2007 10:16 am
by ZaGhost
How did you make out, get her running yet?
I'm working on an XS400K, had her out for a test run and the starting circuit cut off relay crapped out on me, tracking one down now...
When I get her she had sat in a basement for 7 years (gas in carbs and tank...what a mess) Almost have her back to life, but chasing down the gremlins one by one.