View Full Version : Briggs IC Throttle/Carb settings

01-25-2007, 05:22 PM
Hello Everyone!

I'm starting a winter project and trying to get an 8HP Briggs IC engine idling properly again. There's nothing wrong with the engine, i'm just trying to adjust all needle valves and screws back to their original settings. I have included a few pictures to better illustrate what i'm trying to do.

The points are:

1: Top left hand screw
2: Top right needle valve
3: Bottom needle valve which goes into the bowl.

Any and all help will be GREATLY appreciated. the engine is currently reving too high, just looking to bring the idle back where it should be.

Thank you!!

I'm not sure how to imput pics, so please check out this website: http://newjersey.craigslist.org/wan/268374281.html

01-25-2007, 07:35 PM
The pic below shows the starting point for the carb. adjustment. The one to the right is the low speed mixture, One on the left is the engine idle speed, One on the bottom is high speed mixture.

Set the right and bottom adjusters as specified then start the engine, Let it worm up a couple minutes. Set the throttle at idle and adjust the right top adjuster until the engine idles the smoothest. Then adjust the idle speed (left top), Move the throttle to full speed and adjust the bottom until it runs the smoothest, Throttle back to idle and re-check idle speed.

If the RPM is too high at full throttle reach behind the throttle control plate with a pair of needle nose pliers and bend the U shaped tang the governor spring is hooked to as to weaken the spring tension, This will lower the high speed RPM.

Click on this link; http://www.lawnsite.com/showthread.php?t=171667 for adding pics. to threads or post.