My Tractor Forum banner

stuck on a simple B & S quantum engine

1583 Views 13 Replies 5 Participants Last post by  themidniteryder
I picked up a wheeled string trimmer for $20.00 that had been sitting for a few years. The carb was full of varnish but I cleaned it all out and verified the passages were clean. The fuel bowl nut has the gasket and all 3 holes are open and clean on it. The seat had mushroomed out, so I pulled it and replaced it and the float bowl vents out to the atmosphere. I put a new gasket between the air cleaner assy and carb as well.

The problem I'm having is that it will start and run for 1-2 seconds max and then die. Wait 5 seconds, try it again, and same response. The governor linkage appears fine as does the throttle linkage and its all assembled in the correct way. Loosening the fuel bowl nut causes gas to come out at a good stream so fuel is making its way to the bowl. The gas tank was empty when I refilled it so its not an old gas issue.

I'm stumped. This carb is clean enough to eat out of now and its all put together correctly. Next up.. muffler?
1 - 2 of 14 Posts
have you tried running a small peice of wire through the holes? my method is carb cleaner, wire, compressed air & another shot of carb cleaner. best of luck. :trink39:
Whats stumping me about this one is that its starting on a prime. i;m thinking it might have a vent plugged and its vapor locking the carb. this thing is bugging me and its not even my mower!

i wish i lived closer as i would love to give you a hand with it.

one other thing comes to mind, have you checked the intake to be sure its not cracked or missing the gasket?
1 - 2 of 14 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top