Forum

[Count Johnny]

A simple question, for once.


To increase the fuel on the pilot air screw do you turn it clockwise or anti-clockwise?

[Mark M]

Sorry, not as simple as all that! What carb do you have? If it's an Amal, Monoblocs and Sidefloat types meter fuel on the pilot but the Concentric series meter air. However both types increase/decrease the same way so clockwise is less, anti-clock more. REgards, Mark

[jaffa90]

If your talking Micarb, http://www.hitchcocksmotorcycles.com/pi ... s_-_a4.pdf

[Count Johnny]

Mikcarb VM28.



I've read the technical notes (before posting) and I'm assuming that 'out' equals richer. Or am I wrong?

[Alan R]

wrong---------The VM28 is as per the Concentric and meters AIR........so as it's a Right Hand thread then OUT or UNSCREWING = more air thus weakening the mixture......BUT, if you are using the correct method to set the idling speed then it doesn't matter whether it's fuel or air because it's the results of your actions that you're seeking..........

[Count Johnny]

Hi Alan R.


As per my other post, I'm just thinking that I'm slightly under fuelled, as I roll off tick over, and was thinking that I might be able to increase the fuel a little without going to a 2.0 slide. Starting (without choke) and tick over are fine.

[PeteF]

Mmmm, If you are starting without choke OK then you could be rich on the pilot!
Aren't carburettors wonderful (not)

[Count Johnny]

Is it possible (or likely) that I'd get the same effect if it was slightly rich?

[Count Johnny]

Damn this lack editing!



I should clarify that the engine is trying to die as I roll the throttle off tick over.

[PeteF]

Yes I think it could. I had a similar problem with a Tiger Cub. I traced it to a high level in the float chamber which gave a too-rich mixture when just opening the throttle. Wider openings didn't seem to be affected. This might be why you can start without choke as well. Quick way to check is to shut the fuel tap and see if the symptom disappears as the level in the float chamber drops.