Fluctuating high Reving (3000rpm) in idle

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Fluctuating high Reving (3000rpm) in idle

Posted by mark_mowbray at August 15. 2010

1974 Roadster - Amal MK 1 carbs, Tri-spark ignition

Any ideas on my problem? Comments greatly appreciated

Re: Fluctuating high Reving (3000rpm) in idle

Posted by Peter White at August 15. 2010

It could be a number of things but I'd initially suggest you check the throttle cable routing? Sometimes they can get caught up under the tank and cause this sort of problem...

Peter

Re: Fluctuating high Reving (3000rpm) in idle

Posted by mark_mowbray at August 15. 2010

Previously Peter White wrote:

Thank's for your quick response Peter

Although I'm a relativley new member of the Classic bike enthusiast's community, I feel that I can reasuringly persue my passion confidently with the help of people such as yourself.... thank's

Mark

Re: Fluctuating high Reving (3000rpm) in idle

Posted by mark_woodward at August 16. 2010

Hi Mark - I had a similar problem with my 850 fitted with a single Mk2 Concentric - a few things to check:-

1) If you have removed the carbs recently did you over-tighten the flange bolts - this can distort the carb body such that the slide sticks.

2) Check for inlet air leaks - this can cause all sorts of odd faults.

3) Lubricate the throttle cable (assuming that it's not nylon).

4) Check the throttle cable junction box for 'stickiness' etc.

5) Check for frayed cables.

6) As Peter states - check the cable routing for any traps/kinks/tight bends etc.

7) If all else fails you can obtain 'heavy-duty' slide springs for Amals from Burlen - these make the throttle action slightly heavier but seem to overcome many such problems.

HtH

Mark Woodward