**Help with Nikki Carb surging at idle**

[christopher425]

Hey all, I've got a 30" Snapper RER that has a B&S 287707-0225-01 (14.5hp) OHV engine on it. It's sputtering/hunting at idle and I cannot seem to get it to run properly. It doesn't do any better with a load on it either. Below are the things I've tried so far. Any help would be greatly appreciated! I'm about to lose my mind over this mower. I know Nikki carbs are notorious for being difficult, but this is getting ridiculous.

New carb
New fuel lines/filter
Cleaned gas tank
New air filter
Static governor adjustment (set properly)
Fresh gas
New gaskets around the intake manifold, etc.
Idle speed and air/fuel mixture adjustments (could never get it to run smooth)
Springs seem to be good

Any thoughts??

 

[Rivets]

Check your valve clearance. If you need a manual post back and I’ll try to find one.

 

[StarTech]

Check your main jet for loose fitting o-ring.

 

[christopher425]

Check your valve clearance. If you need a manual post back and I’ll try to find one.

I've got them to spec and have checked them twice, but will re-check if I don't see any progress. I believe my problem lies with a cheap eBay Chinese knock-off carb that I bought (I knew it was a risk). Going to visit the local parts store to get a genuine one and see if that is my issue.

 

[cruzenmike]

While I had a different Briggs Engine, it did have a Nikki Carb and experience engine surging issues as well. The solution to my problem was replacing the rubber o-rings on the two carb jets. Over time, ethanol causes the rubber o-rings around the jet to degrade allowing fuel to slip past the jet causing "surges" of fuel into the engine. Since the job is quite easy and fairly inexpensive, might as well rebuild as much of the carb as you can with your tools and the parts provided in the rebuild kit.