Thread: Stromberg carburettor main jet size.

Originally Posted by Gippslander

Seeking assistance on setting up my Stromberg carburettor main jet, my car is a Series 2A 2.25 came with a Holden carburettor and I have set it up as I would for a Holden Grey motor. I haven’t changed the jets just cleaned it and set float level, the engine is running very rich so I was wondering if anyone has installed a stromberg to their car and what jets were installed. Or would I be better fitting an adjustable main jet.

Interesting. Holden Greys are around the same displacement as the Series, one a bit smaller and one a bit larger. I would have thought that a similar jet size would be fine.

I don't remember; is the jet size marked on the jet? I have a Stromberg here from my SIII. If all else fails I could take it apart for a look. I was going to put a kit through it at some stage anyway. It's not high on my list but I'd do it if it helps.

Very long time since I looked inside a Stromberg.

PS. Not meaning to insult you, but the float level is correct?

It is not unknown for unskilled tightwads to drill out jets when they think they are too small.
Suggest maybe a new standard main jet so you know a baseline.
Regards PhilipA

Originally Posted by PhilipA

It is not unknown for unskilled tightwads to drill out jets when they think they are too small.
Suggest maybe a new standard main jet so you know a baseline.
Regards PhilipA

Bought a FIAT with twin downdraught Webers like that once. Jets were like drains, and used fuel at the same rate.

My Series I has a Holden carby but it's fitted with an adjustable main jet.
It does run rich but that's a legacy from the father-in-law setting it up when we drove to the 60th. He was worried about burning out exhaust valves !

Stromberg Adjustable Main Jet - Hume Performance


Colin