Mystery (to me) hose on V12 carb

While restoring the four Stromberg carburettors of my '72, I try to understand each of the different sub assemblies. I think I now know each part and how it works, but there is one vacuum/fuel hose between the front and rear carb on both sides for which I can’t find an explanation.
One end of the hose is connected to a fitting between the Temperatur compensator and the bypass valve. The other end is connected to a fitting at the choke/cold start valve.

Can anyone please explain the purpose of this line?

Thanks, Manfred

Only one carb each side has starting enrichment. The tube passes some of the ‘choke’ extra fuel to the adjacent carb. I fitted clear tube to watch it work.

P

1 Like

Thanks Peter, and a nice idea with the clear tube.

  • Manfred

Pete – can you post a photo?
And where did you source the tubing; can’t take more than 6-8".

Craig

It was 10-11 years ago Craig. All my V12s since have been EFI including the XJ12 I spent time yesterday figuring out which 2 or 3 cylinders were being lazy…

Small bore clear hose from yard tool engine would work but I had bike spares.

According to Richard Russ’s guide book the V12 ‘s originally we’re equipped with a clear vinyl tube for that purpose.