mad tickover

R

RGS-Ned

New member
Hello I wonder if anyone can help me with a problem? I've managed to get my RGS running at last, but there's a little problem that makes it potentialy dangerous. She fires up ok on full choke, reducing to half choke virtually straight away. Then almost closed after a couple of minutes, I'm still trying to sort the idle speed. at present the mixture screws are one and a half turns out. But a gentle blip of the throttle results on the revs rising too around 4000 rpm a staying there for a few seconds after the throttle has been closed. This has never happened before, I think it might be the carb float height. I've tried as near as possible to get 18.5mm when there're closed. Does the fully open height have any effect on running? If so can you tell me what it should be. I've read lots of the carb float posts, but none with the same problem.
Pulling the plugs, she's not running rich, ok infact. I'm about to have the carbs off again to renew some "o" rings. Any help would be gratefully received.
 
Sounds like the term,Hanging idle comes to mind,usually cause by it running lean.Check for air leaks around the manifold.Make sure the choke plungers are seating properly.I spent a couple of hours looking for a lack of power, stalling and hard starting on my old dirtbike today.In the end it  need the fuel tap switched to reserve,chech the easy stuff first.Better start following my own advise.
 
Hi
Have you checked the carb slides are dropping down smoothly and straight away?If it was float height I would have thought it would be flooding or really rich at idle.To rev it needs air so look for ways that could introduce excess air.
Neale
 
Could be something as easy as a sticking throttle cable, or something impeding the slides returning.
On one of my bikes I found the slides were slightly gummed up and the symptoms were exactly as you describe.
I stripped the carbs and ultrasonically cleaned them. Problem gone.
 
Hi,
I'd say you'd got the mixture settings wrong.
Mixture should be set to what ever the motor (cylinder) requires.
Set all the mixture skrews to say approx 2.5 turns out,and then turn each one in turn(clockwise) to achieve highest possible idle speed.A set of vacum gauges would be useful to allow synchronizing of carbs at the same time.
You'll find that you should be able to keep dropping the idle speed down,thus allowing a more accruate setting of mixture skrews.
Don't allow the motor to get to hot.

Andy
 
Thanks for the suggestions, The carbs have beeb ultrasonicly cleaned recently and syncronised. The bike only has 36 kms on the clock so I don't think it's wear on the slides. She was flooding. which is why I checked the float height, and found it to bo slightly out. Nothing appears to be sticking regarding cables and slides. I boiled and turned over the choke rubbers as suggested in another post. I think the air leak Idea seems most likely as there is also a missfire.
So the hanging float height makes no difference to anything?

I'll have a poke about and report back. Thankyou.
 
You must log in or register to reply here.
Back
Top