Series 3 Jet height

I am currently rebuilding the carbs for my Series 3 V12. Does anyone know the correct depth for the jets (as measured from the bridge)? In my search I’ve found recs for anywhere between 0.100” and 0.125”. The jets in my carbs were all set to 0.100” but I’ve no idea if this is right. No spec is given in the workshop manual or the Haynes manual. Thanks for your help.

On my Series 2, I seem to remember that the correct number of turns for initial jet setting was about 65 thou down from the bridge.

Robert, I have this info somewhere as I want to do the same . I’ll try to get the info tomorrow .


Séries 3 have fixed jets…it is the needle that is adjustable .

1 Like

Yes the V12 jets are fixed and the needles are adjustable……just a question of how to install the jets.

Rui thanks for checking!

Oops. Of course. Thanks

Hi Robert,
Jet outer land 2.5±0.3mm below the bridge face (orifice is 0.5mm lower). Info from Burlen Fuel Systems - see here on the UK forum. Stromberg jet height - The 'E' Type Forum.
Hope this helps,

This is a big help - thank you!

Attached the notes I have after speaking to Burlen about one year ago ;

US specs cars 3mm with 0.3 mm tolerance (B1BQ needles )
EU specs cars 2.5 mm with 0.3 mm tolerance

But I have noted down that the distances above are measured ´around the orifice´, not the shoulder ? Unless they meant the Bridge orifice and not the jet orifice ? So this need needs verification as it is not coincident with what @ETypeBob Bob wrote above (very useful link , thanks Bob )


Rui seems like your info pretty agrees with what Bob said. Jet orifice 3mm below the bridge.

Which needles did you end up using? My car is 1971 with manual trans and emission equipment removed and Burlen recommended B1CK.

Thanks again.


I have a US specs car, the needles it came with in 2011 (PO) are the factory ones, B1BQ. But on the front left carb there was another type (can’t recall) but no noticeable difference after installing the original B1BQ.

To all : Interesting enough, I read the discussions on the link @ETypeBob Bob posted above . In one of the postings one Neil (there are two :slight_smile: ) had the very same problem I have : Right bank seems to be running too rich when idling, even when the needles are set as far down as they can go (and yes, choke ok, done that)

On that link on the UK forum, two new things popped up:

(1) Is there a kit to replace the fixed jets by adjustable ones as indicated in the Uk thread ?
(2) Someone managed to replace the jets in situ (!) using a tool supplied by Scandix (Volvo’s) with the carbs in place, I thought that not to be possible. I wonder if it is safe to have the air valve working as a press to push the jet down, did anyone try that before ? It must be a ton or more ! Here SKANDIX - Installation picture Volvo 164, 140, 120, 130, 220, 200: Tools carburettor it seems that the tool is for Stromberg with adjustable jets but Doodsey did it here Stromberg jet height - Page 2 - The 'E' Type Forum for a S3 !

Experiences to share anyone ?


I ended up emailng Burlen and they sent me the table that is attached. Pretty much confirms what as said above.

PB Zenith Carburetter Information.pdf (70.8 KB)

The UK forum also has a very nice excel sheet available that compares the various Stromberg needles: