Air/fuel mixture question...

[Guest Anonymous]

If you richen the air/fuel mixture at idle, would the rpm's increase or decrease? This would be on a tii, but since its mechanical it should respond similar to a carburetor.

[Guest Anonymous]

As you have experienced, if the throttle plate is too far open at idle, the RPM increases until the thing runs out of air for the increasing RPM and then it slows down until it has enough air for the RPM, and then speeds up, and so on ......

If you have an A/F ratio meter on board, you will see the leds bounce left and right in time with the RPM cycle.

Kind of hypnotic.

Closing the plate richens it up (since the pump is not affected by plate positioning) and stabilizes things.