I have a model 31C707 Briggs and Stratton 16.5 hp engine that has a gallop issue. I rebuilt the carburetor replacing the float needle valve and cleaning the carburetor body. I can get the engine to run smooth at idle, but when the RPM's are increased I need to close the choke part way and the engine gallops. I feel it may be a fuel delivery issue, but am stumped as to where the restriction may be.
The main fuel jet is still partially plugged. May need to run a thin piece of wire through it to get it good and clean. Just don't enlarge the hole, otherwise it can cause big problems. Could also be a governor issue. Will running at full throttle hold the throttle steady and see if it runs smooth or tries to die out. If it runs smooth then it is a governor issue.
