Thanks, the oil line was plugged properly. I even changed that line
and put in a new plug. Today I tested it all out....
New lines, new diaphragms, new bulb/hose assembly. Same problem. Just
can't suck gas at anything other than at idle.
At first I had the vacuum line and gas supply lines swapped by
mistake and I noticed gas leaking from the larger diaphragm side. This
leads me to believe there must be an air leak in the fuel pump housing
itself. Both tanks have the same issue, and are clean and not very
old, so I don't think it's them. When I pump the bulb by hand, I can
do full speed.
I just hate to buy a new VRO for $350 and find out I still have this
problem. I don't use the VRO part anyway. It would be a huge help if
someone could let me know if I can just retrofit a different type of
Johnson fuel pump. All the others are so much cheaper, simpler and
probably more reliable!!
What I may try next is putting some gasket material around the parts
of my pump to see if that helps.
Could it be something in the crankcase? I can feel the suction from
the vacuum line, it's a pulsating suction, should it be constant? I
think it's normal anyway. Thanks for the help, I miss having a usable
boat and can't wait to get back out again.