Thread: How to set mixture on Stromberg carbs?

Originally Posted by Bulldog

Don't think you can move the jets on the ones i've got... I had it in pieces and they are fixed in place (can't get to them). I thought the early ones were bottom adjust jets (like p38arover's manual above) and newer ones were top adjust needles (requiring the special tool). BTW, i'm a little dissapointed that i bought the special tool from the UK, and now don't need it

On the ones I had, there was a plug on the bottom of the carb, allowing one of the tools to be screwed in to push the jet up to lean off the mixture.

If the jet had to be pushed down to richen the mixture, the other tool was screwed into the damper hole at the top of the carb (after removing the damper), and the slotted spacer(3rd tool) put into the carby inlet so that the jet could be forced down. A fiddly business, and I suspect Stromberg had several methods to deal with mixture adjustment after emission controls came in.

Top adjust needles, as you describe, seems more sensible than the ones I had.

Cheers,

Lionel

Different markets had different specs. When I was in Saudi my 81 had bottom main jet adjusters.
My OZ 77 had top needle adjusters. There were 2 types of top adjusters, one was a blade like a screwdriver and one was 2 blades with a space between.

I think all had some adjustment, but OZ spec required "non adjustable" mixture.
The ones with top adjustment have self centring needles which do not wear as much as the older version with jet adjustment. In Saudi I had to buy new needles and jets to get mine lean enough to pass the yearly ADAC inspection.
Regards Philip A