Briggs & Stratton 4-stroke mower

[Pete Shew]

No, no manual fuel tap, just the solenoid which stops the fuel leaving the float chamber via the main jet. It was probably developed as a nasty fix for when users turn off the engine at full throttle and are startled by the bangs from the exhaust.

For some reason mine got weak when warm and couldn't pull the needle down against the spring so shutting off the fuel. The solenoid seems difficult to disassemble without damage and as a new one is close to £100! it seems that a 10p set screw was the correct fix.

Pete

[Gib Bogle]

To wrap this up: my trusty, incredibly simple, old B&S is now trusty again. I thoroughly cleaned the carb and tank, changed the oil, and then did the lawn with no sudden conking out. There was no obvious problem anywhere - no water in the oil or petrol, little sediment in the tank - but whatever it was it seems to be fixed. I didn't need to check the points, but should take a look some time. Thanks for all the advice and interesting comments.

[The Natural Philosopher]

Classic bit of grit in the carb behaviour ....

fit fuel filter?

[Gib Bogle]

Where? The carb is bolted on the top of the petrol tank. A tube sticks down into the petrol. It has a gauze filter on the end.

[The Natural Philosopher]

Ah. That should have been enough.