Just a thought Mr. S - the motors on this B9B burner have very little starting torque, and you'll notice that the pump is held into the casing with 3 grub screws.
If these are inadvertently tightened, the pump moves out of alignment just a fraction, binds, and can cause difficult start up. I find the minimum screw pressure helps things.
John
If these are inadvertently tightened, the pump moves out of alignment just a fraction, binds, and can cause difficult start up. I find the minimum screw pressure helps things.
John