Correct adjustment of HS2 idling screws

[rsawatson]

One of my friends has recently enriched the mixture for me, which has brought the plugs up in a nice beige colour - as they should be

However (and this wasn't immediately noticeable at the time, but I suppose it makes sense), the engine was revving ever so slightly more due to the mixture being enrichened. Today, I went to unwind the idling screw (3 in picture) slightly, only to find that unwinding it was having no effect. I then noticed that the fast idle screw (4) was protruding to an extent so as to prevent the idling screw on top of the carburettor from effecting any further reduction in the amount of throttle.

My question is... should the fast idle screw be protruding at all, and if so - what's the ideal setting one's looking for when adjusting both screws? I was just wondering, as to me it seems odd that there are essentially two screws which can control idling speed - although I suppose that there must be a reason for having both of them!

I don't mean to try and tell Granny how to suck eggs by including the diagram - I just didn't want to sound incoherent

Thanks in advance.[frame][/frame]

[simmitc]

With choke knob pushed right in, the fast idle screw should be a few thou away from the cam. You can then use the throttle stop screw to adjust the idling speed. Note that the engine must be at normal operating temperature. The fast idle increases the idle speed when the choke is used for a cold engine.

[bmcecosse]

Back off the fast idle screw till it's clear, and then set the idle speed with the normal screw - making sure a small gap remains under the fast idle screw. It should only come into play when you pull the choke control.......

[rsawatson]

Thanks, its purpose makes more sense now. I shall set correctly tomorrow . Cheers.

[rsawatson]

Thanks for your advice - all running sweetly now!