This is a very interesting thread, as I have recently bought a S/H JC 120se, I had to buy a new pump as one of the terminal was broken on the original, and whilst installing the turbine I have converted it to Kero start, so some good pointers here as to when I run my engine, I'll certainly give the new pump a run-in.

Mark, be interested to find out your findings, whether you have found the cause, and/or cured the problem.

Vince.