Electric Fuel Tap

[j2maria]

I know that most owners replace the electric fuel tap with a manual one; however, I want to keep this machine as original as I can and was wondering if there was any electrical info on the tap.

I get around 12v on one terminal and a click when I turn the switch on. But, there does not seem to be any fuel flowing from the tap. Nor is there any voltage on the other terminal. I suspect the tap is nothing but a solenoid that pulls the tap open when current flows. Since I get no reading at the other terminal it might be shorting inside. Any ideas on how to test this tap? Apologies if this topic has been addressed before but I couldn't find anything on the forum for the 3 1/2.

Joe

[EVguru]

If you're getting a 'clunk' from the solenoid, that tends to indicate that the coil is OK and the core is moving.

Often they're silted up and the diaphram goes hard, if it hasn't actually disintigrated or badly swolen in modern fuel. Most of us still running an electric fuel tap will open the reserve tap when running at sustained high speed.

[j2maria]

Thanks for the reply. I stripped the tap and found the solenoid works fine after removing some crud. The rubber diaphram is swollen as you suspected, making it a tight fit in the bore and preventing it from moving in and out. I need to source a replacement rubber disk.

[EVguru]

Good luck with finding a replacement seal!

You could try putting the seal under a source of heat (incandescent lamp perhaps). It may recover as some of the volatiles evaporate. I only use high octane fuel (V-Power if possible) which contains very little if any Methanol or Ethanol.

[tonup69]

If you're getting a 'clunk' from the solenoid, that tends to indicate that the coil is OK and the core is moving.

Often they're silted up and the diaphram goes hard, if it hasn't actually disintigrated or badly swolen in modern fuel. Most of us still running an electric fuel tap will open the reserve tap when running at sustained high speed.

Nope. Not good enough to just open the reserve tap - or I ride way too fast. I just ended up replacing my electric tap because the bike would sputter and cut out at full throttle. Once I sent to a manual tap, no more problems. But I guess you can tell everyone yours is "original" when I pass you....

[MarkB]

Hmm, I've had no problems running with just the electrotap on the 3 1/2 Sport either with a big handful of throttle at the trackday or at an indicated 105mph on my private driveway. Perhaps it's letting the fuel flow as it should?...

Cheers, Mark.