Engine miss

[Bmwz3coupe]

Bowens 11A-584E765 mower. B&S 3BSXS.1581VG engine. You fire the engine up and after 10-30 seconds it starts a sporadic miss in the RPMs. The spark plug is on the sooty side of black.

 

[Rivets]

Need to know engine number, which are located, stamped on the shroud. Check above muffler or post all numbers on the engine ID tag.

 

[Bmwz3coupe]

3BSXS.1581VG. 275738

 

[ILENGINE]

3BSXS.1581VG. 275738

That is the EPA number not the engine model number.

Looks like the Briggs number is 10H902-0285-E1

Looks like plastic carb mounted on tank. I suspect the carb body has warped which allowed the fuel pump diaphragm to pull out between the carb and tank. The culprit will be directly below the carb where the engine intake pipe connects. Diaphragm pulls out and allows fuel to be drawn around the edge of the diaphragm causing a rich run issue.

 

[Bmwz3coupe]

I will look at that next. Thank you.

 

[Bmwz3coupe]

Replaced the 2 gaskets and it's running perfect now. Thank you for your time.