engine backfires while starting john deere 175

[davefrommd]

My neighbors john deere 175, kawasaki 17hp engine usually backfires while starting. We just removed the flywheel and replaced the flywheel key and it still backfires. The carburetor was previously removed and john deere rebuilt it. We never adjusted the carburetor and was wondering if that could be the problem. I'd be interested in any suggestions or comments. Thanks in advance for your help. dave

 

[Nasty135]

Dave , If it is backfiring through the carb its probably a deposit on the intake valve making it stick open ,But it probably wouldn't run, It sounds as if it runs?? It could be Marginal.
If its backfiring through the exhaust it is probably a burnt exhaust valve, A compression test would help to determin which cylinder is the culprit.
Or it could be the carb dropping to much fuel? Lots of maybees but it all needs to be looked at,
Also is it the first start of the day or every start ?

OH and welcome to TBN... /forums/images/graemlins/smile.gif

 

[johndeere2210]

My guess would be the ignitor. It is a little silver looking box with a wire coming out of it on the left side of the motor. Usually when the ignitor starts going south it will begin with the backfire at start up. That little box is about $35 to $50 depending on where you get it.

 

[johndeere2210]

We just had a 175 in the shop with the same problem described. It would backfire on startup. As the condition worsened, it would not start at all. We ended up replacing the ignition coil and that cured it.