Motorcycle Repair: Backfiring, kawasaki zx6e, compression test

Question
My 1997 Kawasaki zx6e just had trouble starting; it wouldn't.  The battery ran down, so I'm now recharging it.  The interesting thing was that it backfired while I was attempting to start it.  I've never had that problem before and had rode the bike earlier in the day without a problem.

Can you please tell what this might indicate and what I should be checking?

Thanks!

Answer
Hi Jim, hmm..if it backfired that means that one of the cylinders fired while it's exhaust valve was still open. That tells me that a compression test is needed to determine if the valve lash needs adjusted. A cylinder leak down would be best but is beyond most do it your selfers means. Before trying to fire it up again and if possible try and get a compression reading on all 4 cylinders. be sure to remove all 4 plugs first, then test the cylinders starting at number 1 and remember to hold the throttle wide open while testing. If your compression seems uneven between cylinders and/or lower than 100psi, I would suspect valve lash has reached zero. good luck

  randy