How To: Restore a Morris or keep fit

[Mike K]

Originally Posted by Lynn Eades

Paul, about all I know of a Morris Commercial is that they have 4 wheels. However I imagine a mechanical fuel pump and the delivery pressure from one of these is probably about 2 to 3 psi. if your electric pump is delivering any more it can push the needle off the seat and may be giving you a higher than normal float level. This will likely mess up the idle circuit. You might need to fit a fuel pressure regulator? I would put a gauge on it first.

Just to add to what Lynn has written

Some of the older Solex carbies are extremely sensitive to fuel inlet pressure- this I think stems from the days when many cars had the petrol tank mounted in the cowl and the fuel gravity fed down. I found this out after I spent a long time fiddling about with a Series 1 Land Rover Solex carby . In the end the problem ( running rich ) was not in the carby , but in the SU electric fuel pump . The pump spec was 1 to 1.5 psi but it was actually around 3 psi and this oversight caused me much grief along with frustration.