I rebuilt my SUs and have a problem with the cold start carb. Even though the electrical is disconnected the solenoid is apparently leaving the valve open as there is a lot of fuel coming out around this carb
Is the fuel coming out the top of the choke mechanism? If so, perhaps the float level on the front carb is incorrect.
Hard to tell I need another set of hands to start the car while I look at it. However I may have an idea what I did wrong…only tightened the screw on top slightly after I removed the electrical leads and I think the plastic (probably Bakelite) cover which contains the solenoid also seals the valve and hence could leak under pressure
There’s no fuel pressure on the solenoid operated valve.
It only lifts open to allow air through the starting carb under vacuum. Even if it was loose and not closing the most that could happen is the starting carb would work all the time.
If you’re seeing wet fuel on or around the starting carb and you’re absolutely sure the fuel level on the SU it’s attached to is okay - needle and seat are closing, float isn’t stuck and at the right level, vent in the top of the bowl is clear - it’s much more likely that the banjo washers in the bottom are not sealing properly.
Thanks Mike I was hoping I didn’t need to pull the carb off again but I will as I just can’t see any other reason for the leak
Is it an HD6 with diaphragm jet? Both of mine were brittle and leaking. The only time the move is when the jets are adjusted.
Yes HD6 the diaphragms seen fine
I rebuilt them because there was a leak which I couldn’t find…now I can clearly see where it is and it is not where the original leak was so I will get the front one off again and put seals in again and hope I get it…thanks for your help
I had this issue following a rebuild - in my case the tab on the float fork was basically jamming / wedging itself in the open position when the float dropped during installation - this prevented the needle from seating and the bowl was over full with fuel. I had to adjust the float fork a bit, and check there was no binding that would prevent the float from…well…floating…and thus close off the fuel supply.