Fuel tap problems

[ringer]

My electric fuel tap has just recently started playing up. I still hear an audible 'click' when the ignition is switched on, but the flow of fuel is a dribble (when bike is cold) compared to the flow from the manual tap. If I restart the bike after a run (bike is hot) I get no fuel through the electric tap. If I unscrew the coil section on the tap by one turn then the flow increases a little, but then there is danger of leaking. I was surprised that there is no fibre washer between the tube that contains the plunger and the fuel tap body. There is a small recess in the face of the fuel tap body - is it possible that over the years this has worn meaning the plunger does not travel as far away from the diaphragm as it used to?

Reading through other posts on this subject, I am left with the impression that the manual fuel tap has three functions Off / On normal / On reserve. But in my experience, it is either 'off' (lever faces either forwards or backwards) or 'on' (lever points down)

[morinisport]

In the past I recall having to strip an electric fuel tap - not sure if it was on my 31/2 or 500. The moving core of the solinoid had begun to oxidize and it was sticking - quick run over with v fine wet & dry solved this.

Think the manual tap is only on or off - but generally I run with both taps on - and a full tank!

[ringer]

I have dismantled the electric tap, and it is all clean inside. The plunger has no corrosion and it moves freely.

[EVguru]

A new diaphram is probably needed.

There is no official replacement available, but suitable material could be found and one made up.

[alfie600]

the cure i found is to put a small spring inside to help the tap open a bit more the rubber has gone hard with age spiring from a cigaret lighter works well