High idle speed after carburettor adjustment

[Ade Ray]

After reading an earlier thread about brown liquid running down the sides of cars where the carburettors were loose, I enthusiastically tightened the four bolts under my twin 40's which were loose.

 

On re-starting the car my idle speed shot up to 2400 rpm. This I can only assume is due to more fuel getting to where its supposed to go rather than escaping as vapour and depositing itself on the side of my car.

 

the only problem is that the screw that I normally turn to adjust the idle speed has only brought the speed down to 1800 rpm and doesnt seem to have any more effect when I keep on turning.

 

I would be most grateful for any ideas/suggestions

 

Ade

 

 

 

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[Fred]

you may have to adjust the throttle cable if it is to tight it may not let the adjuster go down you may also need to reset the mixture and carbs

 

fredid=blue> eek.gif

[oilyhands]

if one of the carbs has moved closer to the manifold as a result of the tightening then this will affect the balance mechansism between the carbs, its highly likely that the 'slave' carb is open way too much WRT to the master, the salve is the one to which the balance screw adjuster is attached.

 

Oilky

[Ade Ray]

Hi

 

Thanks for the info.It is quite possible that I tightened the left-hand carb more effectively than the right as access was tricky to the right-hand carb. The left-hand carb is the one with the idles speed screw on it. Would attempting to further tighten the right-hand carb improve the situation? Can I get a short term fix (I'm at work at the moment and I dont have all my tools) by attemting to 're-balance' the carbs?

 

Ade

 

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[Graham Sewell]

Do not overtighten the carbs as there is supposed to be some play in the Thackery Washers. If they are screwed rigid, you will get fuel foaming in the float chambers once you start driving. This will lead to fuel starvation.

 

Hope I am not teaching granny, etc...

 

Graham

 

 

Low tech luddite - xflow and proud!

[Graham Sewell]

Damned Browser

 

Edited by - Graham Sewell on 5 Jun 2002 11:12:15

[Graham Sewell]

Damned Browser - triple click

 

Edited by - Graham Sewell on 5 Jun 2002 11:12:44

[Simos]

As Graham says, and reacting to your "enthusiastically tightened" - the rubber washers are not supposed to be "tight" just "tight enough" or to put it another way you should be able to wobble the carbs up and down - they shouldn't be bolted hard to the manifold. (mistake I made teeth.gif)

[Ade Ray]

Hi again

 

I have obviusly taken the comments in the other thread too literally. It sounds like I should ease off the bolts on the left-hand carb to achieve a tight but not too tight end result. I dont think I am suffering from fuel starvation, if anything I seem to be galloping through the fuel at the moment due to my high revs! I think I shall have to go home early and get this sorted out. Thanks for all the advice.

 

Ade smile.gif

 

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