Manual fuel tap issues.

[MartyNZ]

I followed @Lucky Phil's experience and advice and fixed 1 leaking tap. 2 more to go. 

Steps are: enlarge the O-ring grooves, machine an anti-rotation slot in the plunger, adapt screw to make an anti-rotation pin, tap a hole to the valve body, fit bronze anti-friction washers on each side of the knob, put sealant under the anti-rotation pin, assemble with fuel resistant grease. 

@cash1000 tells me that his modified tap is easy to open/close, and it doesn't leak.