Zenith 26VA jets

[Henry Harris]

Yesterday morning was mis-spent trying to get a 1938 Ruby running properly.

The choke butterfly had been set by a previous owner to be open only very slightly. The engine ran wellish but had no power.

With the choke cable adjusted properly it had a gigantic flat spot and would not run. 

Cleaning jets, checking for air leaks etc. made no difference.

I tried 3 different carb bodies, 4 different float chambers of the two sorts and 4 sets of 57/50 jets.

I also checked the Bosch distributor and tried a new condenser.

With every combination there was no change.

However when I tried the float bowl from a 30VM with 90 main jet and 60 compensating jet it performed perfectly.

So, at the moment it's fitted with the 90/60 jets as they are the only alternative I have to hand.

Is this problem caused by modern fuel?

Are other owners running 26VA carbs with non-standard jets?

There was recently a post with photos about which float bowl went with which carb body. I'm unable to find the photos. 

https://www.austinsevenfriends.co.uk/forum/showthread.php?tid=2640&page=2&highlight=carburettor+problems 

[Bob Culver]

Has the car been fitted with a 19mm venturi Austin 10 carb? Or opend out to 19mm? I guess you are beyond the stale fuel trap.