Hello,
I have a base-level 3.5 HP Briggs & Stratton engine that's about 6 years old. It's a throttle-free design with a primer bulb. Lately, after I get it started, it goes in to a rhythm of racing and dropping off about every second. This started rather suddenly. The plug is OK. I started to take it apart, because I didn't even know if mowers had "points". I assume it's some kind of induction ignition system based on the setup of the cutoff switch and the magnetic flywheel. The carb looks like nothing more than a plastic throttle body, and I don't see a float/bowl of any kind. I generally don't repair mowers, obviously. Does anybody recognize that surging/dropping behavior? Thank you!
Thanks,
JM