Old Tilly Carb Question

[redtractor]

What is the brass screw?

 

[Chainsaw Jim]

That is the rev flood limiter.

 

[redtractor]

Never heard of it. Don't stop there. Teach me something.

 

[Chainsaw Jim]

When the velocity of air flowing through the carb reaches a certain level from high rpm it releases excess fuel to flood and slow the engine.
You can disable it by plugging the passage beneath. Most use a small cut out of aluminum can. Drop it down there like a washer and tighten the brass plug back down.
It's there for good reason. If you're not needing a hotrod then only do it temporarily to tune the saw when you don't have a tachometer.

 

[redtractor]

OK. Sounds like another passage to keep in mind while cleaning. Thanks