Adjustment of a new B&S OEM 799728 by Nikki on my Snapper RER 10HP B&S L-Head?

[GAJoe]

I bought the Snapper RER that was running rough. When I tried to start it some times gas would come out of the carb intake flange, O ring leaking! I did a rebuild on the Chinese Nikki copy' including the tiny, tiny O ring on the main jet that came from the Kohler rebuild kit for Nikki carbs. That helped but it was still surging at idle until I closed the fuel supply valve, then it would idle smoothly. My neighbor that's pretty good with small engines said that the knock off carb is slightly flooding still. I had read that most surging with the Chinese carbs were fixed by enlarging the idle jet oriface but I think that I was getting too much fuel. I cant find a Walbro that is listed on the parts website as unavailable but I found a genuine new old stock B&S 799728 by Nikki that was listed as the gravity feed carb for $40 on Ebay and got it. I replaced the two O rings that usually fail and result in flooding with Viton O rings and installed a better fuel filter to hopefully avoid problems. I replaced the Chinese carb with the new B&S OEM and made sure that the governor was set properly. I started it and let it warm up. The surging problem is gone . When I lowered my throttle to minimum setting it died so I got my tachometer and adjusted my idle speed screw to 1750 RPM. The tachometer shows that it is running about 3100 RPM at max throttle. Correct me if I am wrong, that RPM is controlled/adjusted by the tension of the spring on the governor. I could bend the tab to change that, correct?
My main question is about adjusting the fuel/air mixture jet setting. I have been unable to find that proceedure anywhere. The engine origionally had a Walbro LMT carb I do believe as the service manual that I downloaded doesn't have the proceedure for a Nikki made carb. I am refering to B&S SM 270962 Single Cyl L-Head Sec03 Carburetion. I did find the LMT instructions on pages 47 & 48. Would this same proceedure work for the Nikki?

 

[Auto Doc's]

Those instructions have been reliable for many years and are just a basic guideline for a set point before stating the engine and warming up. Once running minor adjustments may be needed. Listen carefully how the engine responds to these adjustments. The goal is to adjust until you get the smoothest running and best power.

I set main fuel mixture needle adjustment first at high RPM and then the idle mixture at idle accordingly.

No two engines have exactly the same adjustment settings and adjustments may need to be slightly changed from time to time.

The top governor speed is usually adjusted by bending the tab gently where the governor spring attached to the bracket. Do not exceed 3600 RPM. As for idle, it can be set where the engine sounds "comfortable" and not struggling to run.

"L" head engines rely on splash and slinger oiling, so the idle RPM cannot be too low. It is never a good idea to let these engines idle for extended periods anyway.

 

[GAJoe]

Thanks for the reply. Sounds like I'll need the neighbor to help when he has time to. He has lots of experience and would know how it needs to sound.