v twin 20hp not running right

[jimmy40]

I took the Carb apart again, this time I pulled the air butterfly rod, and found that a foam ( gasket) had disintergrated. I have several new foams but not sure which to use or how they go in, is a metal gasket need to go with it? would this cause my problem ( I think it could) does anyone have a break down on the Nikki 498751 266 1717-091 carb?

 

[bnwood]

I am having almost the exact same issue with my 20hp (407777 0124 E1)

I found this link for the carb
http://outdoorpowerinfo.com/repairs/briggs_intek_v-twin_carb.asp
http://outdoorpowerinfo.com/repairs/briggs_intek_v-twin_carb2.asp

 

[jimmy40]

The foam was causing my issue. Then I found spring bad on governor. It is running perfect again.

 

[Tinkerer200]

You didn't post the code numbers so don't know age of engine NOR manual. First Service Manuals had incorrect valve adjustment instructions saying to adjust AT TDC later bulletin corrected to 1/4" down past TDC. High octane fuel will do you no good engine is not designed for it. Whenever carb is removed, Gov Static adjustment should be checked, reset.

Your symptoms indicate bad air leak OR bad carb passage blockage.

Walt Conner

 

[reynoldston]

I have found through the years of repair that when a engine hunts you have low speed problem. Some where the low speed circuit is plugged inside the carburetor. It doesn't take much to plug it.

 

[jimmy40]

The foam on butterfly shaft was causing my issue with hunting. After fixing that I found the spring on governor wouldn't allow to return to low idle properly. I have corrected both and all is good again. Thanks for all the help. And yes my valve are set to the latter of 1/4 past Tdc.