Briggs engine running real rough

bob2001

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I have a Briggs 21hp 407577 0292 E1 engine that I just put a new carb kit in. It starts easy but after about 2 seconds it starts to smoke (white gas smelling) and runs really rough. It has no HIGH speed on the throttle. When i push throttle up it stays same. Governor seems to be real stiff but when I took the springs off...governor seems to be free and easy. Once in a while I can start it and move governor up and down and it will start to tun at a higher speed but then slows right back down. The engine also pops a lot when running. Seems that if I mess with governor it smooths out and sounds good but doesn't last more than a 1/2 minute then back to bad idle and popping. Any suggestions?
 

Fish

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Sounds like when you went through the carb, you lost the high speed jet, which is real easy to do on those junk carbs.

Carb
 

bob2001

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Not too familiar with this carb. There are no adjustment screws except the idle screw. Where would I find the high speed jet on this one?





Sounds like when you went through the carb, you lost the high speed jet, which is real easy to do on those junk carbs.

Carb
 

Fish

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Click on the link I put up, the jet is ref # 117, it is just pressed in, you likely lost it when you cleaned the carb, the o-ring is the only thing that holds it in place, with it missing, you will run, but run rich as hell!!!!
 

bob2001

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Click on the link I put up, the jet is ref # 117, it is just pressed in, you likely lost it when you cleaned the carb, the o-ring is the only thing that holds it in place, with it missing, you will run, but run rich as hell!!!!

Where is the main jet located? Doesn't show precisely on diagram.
 

Fish

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Likely just lightly pressed into that silly plastic piece in the bottom or the side.... I hate those carbs.......
 

bob2001

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Thank you. That was the problem. Went ahead and ordered a new carburetor. Found one for only $24.95
 

Fish

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Yeah, I did something similar on my first encounter with them. Using my air gun I blew that jet somewhere into the next county.
 
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