Briggs Intek, replaced everything, still surging.. Ideas?

[Gord Baker]

Your description indicates that it is running in a lean condition. Try giving it a small bit of Choke. If that cures it, then you need a carb /cleanout/rebuild, perhaps opening up the main jet beneath the Emulsion Tube a tiny bit. Remove hose at filter and Run some Carb Cleaner directly into the fuel line.

 

[mcspeed]

The valves need to be taken out and cleaned. The surging is the intake valve not closing all the way. Im also guessing that the exhaust valve is carboned right up and its not closing all the way either, hence the back fire.

Valves were fine…..read the follow up post.

 

[kjonxx]

Will check tonight

Check the flywheel key

 

[Jpeters]

Own a JD La115 with an Briggs Intek 19.5 engine. Have an issue with surging and backfiring when not under load. Have replaced fuel filter, gaskets, carburetor, spark plug, fuel pump, ignition coil/spark plug wire, air filter, adjusted valves, pumped out and refilled gas tank. Still have a surge/race condition and random backfire happening at any throttle position while at rest and during movement, it does smooth out when I engage the mower blades. I noted another post about surginng which indicated that the safety switch could somehow be involved, not sure I understand hwo that could be. Completely out of ideas and open to suggestions.

A lean running engine will cause the governor to act like this. The new Carb you put on may not be jetted properly especially if that is a cheap Chinese knockoff.

 

[JimP2014]

Where's the guy with the original problem is he still around?

 

[Freddie21]

I have induced surging, many times, by using an Amazon type carb. Clean and rebuild the OEM carb.

 

[electech2]

Had the same problem back in the 90s on a Kohler Command 15.5 hp. Finally found the governor spring to be slightly too tight (possibly due to my repairs and guessing at the right hole). Moved the spring one hole lighter and she purred like a kitten (still does).

 

[loncherokee]

Own a JD La115 with an Briggs Intek 19.5 engine. Have an issue with surging and backfiring when not under load. Have replaced fuel filter, gaskets, carburetor, spark plug, fuel pump, ignition coil/spark plug wire, air filter, adjusted valves, pumped out and refilled gas tank. Still have a surge/race condition and random backfire happening at any throttle position while at rest and during movement, it does smooth out when I engage the mower blades. I noted another post about surginng which indicated that the safety switch could somehow be involved, not sure I understand hwo that could be. Completely out of ideas and open to suggestions.

did try some seafoam will clear out the carb.

 

[loncherokee]

seafoam

 

[bartles]

You might want to see if you can use the jet from the OEM carb in the new carb you recently installed. I've had to do that in carbs I replaced due to excessive corrosion because of bad gas/without fuel conditioner.