New kit in nikki carburetor and still surging and sneezing, why?

check with dealer or a repair shop

Normally, you just go by the Briggs and Stratton engine and model numbers. B&G carbs

https://www.google.com/search?q=replacement+carburetor+for+a+18.5+brigs+and+Stratton

Or Walbro

https://www.banggood.com/buy/briggs-stratton-carburetor-walbro-697202.html

I would be surprised if Jack didn't have one!

Briggs and Stratton 31E707-0111-E1 Parts Diagram for ...

https://www.jackssmallengines.com > briggs-stratton > c...

Briggs and Stratton 31E707-0111-E1 Carburetor - Walbro &Nikki, Cylinder Head, Fuel Supply, Kit - Carburetor Overhaul - Walbro & Nikki Exploded View parts lookup by model. Complete ... (Carburetor Part Numbers 696179, 697202). $6.18.

https://www.google.com/search?q=Walbro+697202

..

depends on what you are working on. i would say the carburetor is still dirty inside, if it is not cleaned properly it will do as you are saying. a engine sneezing is a new one for me though.

Governor "hunt" is almost always a carburetor or intake air issue. Check the carburetor mounting bolts are not loose (causes vacuum leaks between carb and intake). Suggest you drain and replace fuel with fresh fuel, check for water in fuel. Don't forget to drain the carburetor fuel bowl (may be try this first).


If still hunting, likely carburetor is fouled, try cleaning and or replace.

Make sure there are no vacuum leaks on the engine manifold side of carburetor. There are 3 o 4 pieces on the engine side so inspect well.

If no leaks on engine manifold side then likely there's a blockage somewhere in the carburetor high speed circuit. Most economical solution is chinese knock-off for ~$20 US delivered.

If you can't find a cheap replacement then you'll need to do a deeper clean of carburetor by removing welch plugs and submerge in carb cleaner. You will need new welch plugs (kit) and likely kit will cost more than a knock-off carb.

Before tearing down carb, you could try Seafoam fuel treatment... probably less the 50:50 chance it will clear.

briggs stratton nikki carburetor

Kit Carburetor Overhaul Nikki Carburetor

Cleaning the carburetor is a good starting point. There is two versions the Briggs that were used on this mower. One had a single barrel and the other had a two barrel version. Both were Nikki carburetor that main jets that are held in place by tiny o-ring that shrink causing the jets to leak extra fuel causing surging.

Most likely the Nikki carburetor needing a good ultrasonic cleaning and a carburetor repair installed. It would be best for regular lawnmower repair shop to do this as the Nikki can a pain to get the parts replaced correctly and even the new gaskets can leak sometimes.

you should look them up on the web or look at the difference in the rebuild kits for then

remove the float bowl cover and set the wet float level. There should have been instructions with the rebuild kit on how to do this. If you don't have experience with carburetors, ask an old mechanic to help.