Wilsonrl48747 0 #1 Posted July 14, 2009 On my 312-8 with the Kohler 12hp, the carb seems to be "self adjusting" when we use it. I went over to my sons and he was running it with the choke fully engaged, as soon as you push the choke back in, the motor wanted to quit. I readjusted the idle speed screw and got it running fine with the choke fully open. Stopped and restarted, idled down nice, no hesitation or popping. They finished mowing the lawn and put it away. Now when the go to run it, they have to keep the choke half on or it will stall. It seems like vibrations are rattling the adjustment screw, but I am not sure. Would a teeny drop of thread lock fix the issue, or am I looking at something more complicated here? :thumbs2: Share this post Link to post Share on other sites
TT-(Moderator) 1,131 #2 Posted July 14, 2009 There are friction (tension) springs on the adjustment screws that should keep them from moving once they are adjusted. I've never had a problem with one moving on its own though. My hypothesis would be a dirty carburetor. If you are capable, remove the float bowl on the bottom of the carburetor and look for any contaminants. If the tractor doesn't have an inline fuel filter, now would be a good time to add one. If these two things don't help with the problem, pull the carb and give it a good cleaning followed by a "rebuild kit". Share this post Link to post Share on other sites