Posted by David Sherman [162.158.41.18] on Wednesday, May 01, 2024 at 15:38:27 :
In Reply to: Briggs and Stratton posted by Jerry in Idaho [172.71.151.145] on Saturday, April 27, 2024 at 15:50:41 :
Also could be a major air/vacuum leak. Are the intake gaskets good? No plug for anything fell out? I had a truck once where it ran fine until I stopped at a rest area. Then when I went to leave it would only run with the choke pulled out all the way, at which point it also ran very fast. Turns out there was a pipe plug in the intake manifold that had managed to unscrew itself and fall out. Vacuum just have been holding it in place until I parked, because I found it on the ground under the engine. Screwed it back in and all was good.
In both situations you're describing, you're giving it lots of extra gas to keep it running. That suggests its getting too much air. You can "sniff" around with a piece of rubber tubing connected to a propane torch valve assembly (without the burner) to find where the leak is.