Hi yet again!

Tuning a 1 1/4inch SU carb and looking at it from the front of the car, which way do i turn it to richen and weaken the mixure?

From the angle of the screw being pointed away from you (looking at it from the front of the car), does turning the jet screw clockwise lean up the mixure or richen the mixure?? I have been studying the leyland diagrams and to a newbie it is totally vague.

When tuning the carb, should I start rich or lean? This is also vague in the tuning section of the manual...

Thanks!
Chong

Looking from the top of the carb, clockwise will richen. In effect by unscrewing the jet you are richening the mixture, and by screwing it in you are leaning. Pull the choke out and you'll see what I mean - the further down the jet is the more fuel.

A baseline start is to screw the jet all the way up (ie lean) and then unscrew it 12 flats, and work from there.

Do you know about the dashpot lifting pin? I can't remember if the manual mentions it or not but basically when idling, push the pin up slowly (right side of carb next to float, pushes upwards). If the revs rise and continue to rise it is too rich, if it doesn't rise at all, but starts to stall you are too lean. Your looking for a compromise, engine revs rise a bit then steady out.

Anto.

Thanks Anto,

Yeah i know about the tuning part, just wasn't sure which way was rich or lean

Thanks! I will tune her tonight