Thread: Idle speed adjustment

Hi Dan,

I haven't played with the Solex but usually there are two screws, one adjusts the idle mixture the other adjusts the idle speed. The one that just adjusts speed is usually somewhere on the fitment where the throttle cable or rod come in to the carbie. So basically it adjusts the position of the throttle plate at idle. The other is usually on the base of the carbie and adjusts the mixture so can make it richer or leaner at idle and usually the revs will change as well but this is not really it's primary purpose.

If you are adjusting idle revs you may also want to adjust the timing (or maybe that is why you need to adjust idle since you were having pinging issues I believe ).

Tim.

Originally Posted by Timj

Hi Dan,

I haven't played with the Solex but usually there are two screws, one adjusts the idle mixture the other adjusts the idle speed. The one that just adjusts speed is usually somewhere on the fitment where the throttle cable or rod come in to the carbie. So basically it adjusts the position of the throttle plate at idle. The other is usually on the base of the carbie and adjusts the mixture so can make it richer or leaner at idle and usually the revs will change as well but this is not really it's primary purpose.

If you are adjusting idle revs you may also want to adjust the timing (or maybe that is why you need to adjust idle since you were having pinging issues I believe ).

Tim.

I reckon you might be right, Tim. I wanted to go to the AGM in Matilda, but I don't want to damage the engine. As I don't know anything about this, should I not use her until I've had the timing adjusted and/or idle speed adjusted?

Not sure where to get this done, as I think Dave is away at the moment and I'd be better attempting brain surgery.

Symptoms: Vehicle now "farts" off throttle as I decelerate. Can almost stall at idle as revs too low. Now needs choke to begin drive - I used to be able to start on choke, then within 30 seconds push choke in and burble away on idle until warm - then set off.

the on closest to the firewall, is the idle screw. No you do not have to touch the mixture screw.
Dennis

I'm definitely no expert, but having to have the choke on to run would suggest that the carb is running too lean. Wonder what others think? Also if by "farting" you mean slight backfiring then i would also suggest checking the points gap. Lyall

My S1 solex gets a blocked jet from time to time giving the lean running symptoms. Goes okay only with choke and spits-back into the carbie. I cant remember which one was the culprit, but it might have been the main jet?

Thanks for the help everyone. Killer checked the gap for me - it was spot on. I suspect the timing is too. After talking with other S1 drivers, I think the clattering sound from the engine is just normal operation!

Killer raised the idle speed a touch and it's running sweetly again - no farting off throttle - and no oil leaks.