QuestionI have a weed eater 20" mower with a briggs &stratton model 9s502-1019-b1 engine. I lost the carb mount screw, and as a result the intake manifold broke. I replaced these parts and now when i fire it up, the Idle bounces up and down, almost to the point of the engine shutting off. I am a Harley Mechanic by trade, so I am very comfortable working on anything, but I really have no experience with governors....... would an intake leak do this? or is something up with the governor?
AnswerA leak could cause the problem but the is not very many places for a leak to happen...one piece intake tube. I'm assuming the gasket is new.
I suspect it is just a dirty carb. Those carbs are pretty sensitive...EPA enforced rules.
I would remove the carb and clean it by blowing compressed air through all the orfices. Take the fuel intake screen off and blow the screen out. I've had trouble in the past with early model screens...those holes are very, very small.
The pneumatic, or air vane, governor you have is pretty simple. Just make sure the linkage is not binding and the pivot bolt area/hole is clean and moves freely.
Let me know if cleaning the carb fixes your problem. FYI, there are several You Tube videos on cleaning those carbs.
Eric
