I have a B&S 44R877-0001 that started surging out of the blue one day. I've replaced both park plugs, added a carburetor cleaner to the fuel. I mowed a few times hoping that it was just a gummed up carburetor but that hasn't helped. This model has a vane and temperature controlled lever that is supposed to engage and disengage the choke. It's almost like the spring that keeps the vane forward when the engine is off is too weak and the vane pushes back completely even at idle. Once the vane is pushed back the rpm drops and as the motor is about to die the air force on the vane drops enough that the choke disengages and the motor revs back up. This keeps repeating itself. If I manually hold the choke control arm up against the temperature actuated lever the idle evens out. I don't know why this is happening but I'm wondering if I can just remove the vane and bypass the auto-choke feature? Thanks to anyone that has advice!
Thanks for the reply! If it's a dirty carb how come I can get it to idle decently when I manually disengage the choke? I would expect bogging at high revs if it were the choke, but there is none.
#4
Scrubcadet10
surging is caused by a lean running condition, which is too much air and or not enough fuel.
While what Scrubbie said is true, you can get similar symptoms from a faulty auto choke, particularly when the springs get a bit tiredI rip them out & fit a manual choke and have no more problems
Dirt trash in low speed circuit of carb. engine starts to die rpms drop gov. spring opens the throttle engine revs up and gov. tries to balance the rpms engine starts to die again and it starts the cycle all over again.
