Thread: 1985 County V8 SU Carb Mixture adjustment

The manual shows an SU carb not a 175CD stromberg, which is what you have. The fuel mix is adjusted down the middle from the top using a special tool. Generally unless someone has monkeyed with it there shouldn't be a need to play with it....


Jc

most likely the linkage has gotten sloppy, the carbs need cleaning or the dashpot oil needs replenishing. This tends to lead to the balance of the carbs being out more than the mix being off.

if the internals of the carbs are gummed up or the gallaries are blocked that will cause lean running.

They are probably just ashamed of their appearance.

First thing to check is if the diaphragms are OK. Undo the four screws on top and pull the top off and check to see no holes in the rubber bit.

If you get desperate and are willing to come to Avoca Beach I have a Unisyn, Colortune and jet adjuster( although there are 2 types)
Why do I keep this stuff?
Regards Philip A

Thanks for the replies.

The problem I have found (and suspected for a long while) is she is burning rich...you can smell the petrol at the exhaust when it is idling, and the plugs were all very black with carbon build up....and it uses plenty of petrol (18-19 litres/100ks).

What I have are twin carbs of course, SUs, which are pretty clean inside and I have the oil in the pots at the right level. Needles are not bent.

The choke cable is completely relaxed when not in use.

So the question is "how do you adjust the mixture on the carbs I have.(or are they factory preset and in fact not adjustable)?"

(BTW I have bought a vacuum guage to check the air flow to both carbs for balance purposes)

under the oil is the needle adjustment, you need to adjust the height of the needle relevent to the piston.

lowering the needle leans it out, lifting it riches it up.


lots of attention to detail when you're doing it, its very easy to get the mix balance off left to right and burn up one set of pots.

from the picture you posted, it is most likely that you have Stromberg carb and not SUs.