12HP Briggs&Stratton High Idle.

wcpost

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I have just re-ringed a 12 HP Briggs & Stratton. The problem I am having is the motor will only run with the choke on. I have cleaned the carb with my tip cleaner and I can't find any obstructions. I have even replaced the carb from a running motor and I am getting the same results.
When the choke is closed, the motor gets less air to mix with the fuel; does this mean it is sucking air from somewhere else or something else?
 

wcpost

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I thought some one out there would have had this problem. Guess not.
 

bwestbrook

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Sounds to me like you might be sucking air in somewhere causing it to run lean. Check to make sure everything is tight and that your gaskets sealed when you put everything back together.
 

pugaltitude

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I would go for possible lack of fuel flow than sucking air.
The choke is guiding air into certain parts of carb to push more fuel up into engine.
Check for blockages and fuel lines are routed correctly and make sure carb is cleaned correctly.
Also check core plugs on carb are correctly fitted and sealed.
 

SONOFADOCKER

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Sounds like my Kohler that had a leak on the air fuel meter screw. . Swapped the screw with a donor and issued stopped .
 

wcpost

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OK guys here is the scoop. I had a second motor in my shed; you know you can never have enough motors lying around. Swapped the two out and the replacement motor was doing the same thing. Only running with the choke on. Then it hit me, when you first start one up, you run the metering screw all the way in and then turn 1-1/2 turns. Give or take a few. Fired up and once it warmed up I was able to adjust the mixture and idle. Runs fine. It wasn't the motor after all. You all were on the right track on starving fuel. Now I have a fresh 12HP in the shed when I need it.
Thanks for the help.
 

Fragger

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Good info thanks for sharing!!:banana:
 
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