Repairs STX 38 NOT STARTING

[LOTGUY]

GOT MOWER AT AUCTION. NEEDED NEW BATTERY. RAN FINE FOR A WEEK. WOULD NOT START. BACKFIRING. CLEANED FUEL FILTER, CARB., AND SPARK PLUG. RAN FINE FOR A WEEK. BACK TO BACKFIRING. WHEN IT BACKFIRES FLAMES COME OUT THE BREATHER. IDEAS?

 

[RatRacer]

The STX 38 was my first JD. Wife's cousin borrowed it for his lawn care business, because his main ZT died, and I never saw it again.(but my lawn was cut every week for 8 yrs after:laughing

I would check the flywheel key for being sheared. That will cause a timing issue, leading to the back firing. It was an issue with this model.

Hope that helps.

 

[LOTGUY]

I CHECKED THAT. KEY WAS IN PROPER PLACE. LOOKED AT VALVE SPRINGS. EVERYTHING LOOKED GOOD THERE TOO.

 

[Rivets]

Does this have an adjustable carb. If so try leaning out the high speed mixture. If not, double check the float level and make sure it is closing. Please turn off the caps lock.