31p777 briggs stratton engine

[JAMES40]

I have a 31p777 briggs intec vertical engine ,when i go from idle to full throttle it bogs down and then returns to top no load speed ,i cleaned carb good i checked fuel flow it is good i checked fuel pump it is shooting fuel out ,the airfilter is clean it has fresh fuel i cleaned tank when i clean carb i also replaced fuelfilter ,i tried adjusting idle mixture needle but no improvement ,i checked for binding in throttle and governor arm there is no binding i checked when i had carb off for cleaning when i cleaned carb i saw carb cleaner come out of transition and idle mixture progression holes so they are not stop up i also cleaned main emulsion tube and main jet with a tag wire and carb cleaner.The engine runs good when top no load speed and when i engage blades it runs great no skipping at all under load no black smoke i also changed the oil with new oilfilter.

[Walt 2002]

Sounds like lean idle mixture. I assume that has a limiter cap on it and I don't know how you cleaned that part without removing the idle mixture screw. I assume you know what to do about it.

Walt Conner

[JAMES40]

When i cleaned carburetor i took the idle mixture screw out and sprayed cleaner through passage and jet idle i also used a tag wire and went behind and blew out with compressed air ,if you give gas very slowly the engine will not bog down it will go from idle to top speed with no hesitation but if you give it gas quickly it will bog down ,as i move throttle lever to wide open i can see the governor move all the way back but it seems it does not respond very quickly when imidiate throttle is given and then governor will move to halfaway point between top no load and ilde.

[bgsengine]

idle mixture is still lean, if you had the screw out, then it must be adjustable - open it up a little more to give it some more gas. That or the carb is not cleaned right, float level is too low, or blockage in idle feed circuit from carb bowl to idle passages