Rich running

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GTC Ian
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Rich running

Post by GTC Ian » Tue Jul 30, 2019 10:55 am

Having spoken to Fast Road Cars, the problem for the rich running is partly due to the fast road cam Ive fitted and the carb being fitted with an anti stall diaphram.
He informs me that I have to blank of the anti stall and pipe going into the carb base. Has anyone on here had the same problem? All help gratefully welcome
The carb is a 38 DGMS


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Rich running

Post by AJL Electronics » Tue Jul 30, 2019 11:18 am

GTC Ian wrote:
Tue Jul 30, 2019 10:55 am
Having spoken to Fast Road Cars, the problem for the rich running is partly due to the fast road cam Ive fitted and the carb being fitted with an anti stall diaphram.
He informs me that I have to blank of the anti stall and pipe going into the carb base. Has anyone on here had the same problem? All help gratefully welcome
The carb is a 38 DGMS
That sounds like a complete nonsense to me. If anything I would expect a hairy cam to want more fuelling, not less. Isthe carb jetted for standard?


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Rich running

Post by GTC Ian » Tue Jul 30, 2019 11:43 am

It has 50 idle jet and mains 142


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Rich running

Post by AJL Electronics » Tue Jul 30, 2019 11:55 am

Well the idles should be .45 but there is not that much of a difference. You should still be able to tune that out. I think I would have the jets and volume screws out and use an airline to ensure that the passages are clear. There are two calibrated "air intakes" on the top surface of the float chamber. They are fairly obvious because they have brass inserts. Check that they are clear.


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Rich running

Post by GTC Ian » Tue Jul 30, 2019 2:21 pm

Ive just used the airline to ensure the passages are clear. No sign of any blockages. Emulsion tubes look clear.Ive just placed the carb body on the surface table and I have a .3mm bow in the base. I am presuming that if air is getting in there ( gasket not adequate to seal this size of gap) and I am compensating the extra air intake by increasing the idle speed and mixture, that this could be the cause of the rich mixture and sooty deposits on the plugs. I had done the brake cleaner trick before I took the carb off, but being unable to lower the tick over I didnt hear any increase in speed.


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