QuestionQUESTION: I have a John Deere 260 with a 18hp Kawasaki engine,FC540V-
BS00. Was running fine, backfired out the exhaust sounded
like a shotgun, and slowly quit running. When trying to
restart it shoots fire out the carb and the exhaust, with a
great big bang. Checked the valves, seem to be set right,
the flywheel key is not sheared.New gas,filters and oil.
Timing,cam gear? How do you set the timing? Had new rings
about 10 hours ago. Any ideas would be greatly appreciated
as we are stumped! Thanks
ANSWER: With the valve covers off and spinning the engine by hand, do the valves move? Some of the Kawasaki's have plastic cam gears, I'm not sure about yours. They break or strip from time to time and jump time. It sounds like you're going to need to tear the engine down again.
I'd start by checking that the valves are moving and that they are closed with the piston at Top Dead Center. I think you're going to find that they're not. Let me know what you find from that and we can go from there. Thanks, PK.
---------- FOLLOW-UP ----------
QUESTION: Well, we took off the valve cover and the valves are working
OK, compression great, and after not finding anything wrong
put it together again and it ran fine. Could the carburetor float or needle have stuck open and been dumping excess gas
in the cylinder to cause this? If you think it could be the
problem will get a carb kit. I would have bet it was timing
the way it was acting!
AnswerIt could have been loading up and doing this, but it certainly didn't sound like it. But you can't argue with results, so rebuilding the carb would be a logical next step. I'd just keep a close eye on it and if it starts running funny, shut it down and look for a problem. The sort of backfiring you describe can easily bend pushrods and cause other damage so I'd be cautious with it for awhile. Thanks, PK.
