fuel valve 20 E

[john firth]

After reinstalling the tank in april,  the engine would not run without choke.

Investigation showed a serious air leak in the supply side; this was due to

an unseated taper thread on the tank coupler to the valve.

The valve has a remarkably small internal diameter 3.1  mm;  there must be

a substantial press drop  at full flow. However this seems to have been

original equipment  and the engine manages 6000 rpm.

Has anyone else examined the shutoff valve for restriction?

I am tempted to drill it out larger.

cheers

John F