Fuel tap leak

My fuel tap has a small but steady drip when closed. Do I need to worry about this??

Not if you're fireproof.

Neil

Unless you are talking about some sort of mechanical device, I'd suggest that you get your prostate checked!

John

Fuel tap for what? The only experience I have with these would be with the fuel tap on my BSA D1, which is a push-pull action to open/close the flow and uses a small cylinder of cork on the plunger as a seal. this can dry out over time and shrink/disintegrate, causing a leak.

I think replacement cork seals are available, but if not, I've heard of people 'whittleing' then from a wine cork. They drill a through hole the size of the plunger's inner spindle then carefully carve away the remaining cork until they et a good fut in the valve.

cheers

P.

I think I have seen fuel tap corks at one of the Villiers spares sites. Colin

Modern petrol contains ethanol and has a detrimental affect on some seals and taps on older bikes.

**LINK**

Windy

Drop it in boiling water for 10 minutes, you'll find it will swell enough to stop the leak.

Yeah an internet search told me about the corks, got some new ones on order!

Just occurred to me I have some bits of Delrin lying around, I wonder if they would make a good seal??

Edited By Wolfie on 28/11/2015 20:17:32

I would expect delrin to be too rigid for a petrol tap "cork" ;it needs to compress a little. Colin

I've used PTFE bar to make seals that may work.

Martin P

You most certainly do need to worry about this.

I have the same type of push on/off tap on the Austin Sevens' under-bonnet tanks, that if they leak (mine do), can deliver very accurately a drip directly onto the hot exhaust. Then it's whoosh! No car and perhaps no me.

Don't faff about with wine bottle corks, or Teflon inserts (I have and it doesn't work) or with trying to over-tighten the joint with Mole Grips. Get new seals or, better, a replacement tap. These are readily available for the Seven and I expect they are from the specialist suppliers for whatever it is you have.

Good Luck

Martyn

Removing ethanol from petrol is relatively simple. You need a clear plastic container with a drain tap at the bottom. Fill with 10 ltrs of petrol and 1 ltr of water and shake vigorously. Leave it to settle overnight and the ethanol and water will settle to the bottom, then just drain this off.

I don't think you have anything at all to worry about.

His fuel tap was leaking two years ago and by now all the fuel has run out.

If it's leaking externally, there's a fair chance it's leaking internally, so fuel flows to the carb, float needle may not handle it, and then it's passed the carb into the inlet port. Motor in the wrong position, In valve open and it's in the engine. Not good.

Fuel taps HAVE TO work and be in GOOD condition.

Martyn, I guess your 7 is pre 1933 then ? I made the corks for my '32 RN from wine bottle corks back in 1998 - and they are still working OK.
BobH

My understanding is that modern fuel contains ethanol as a means of raising the Octane rating without the risk of detonation, to counteract the removal of lead. Control of detonation was the main reason why tetraethyl lead was added to 'leaded' fuel. Since the use of lead was banned, fuel chemists have tried a number of other ways to maintain the octane rating of the old 'super' fuel without the detrimental effects of unleaded fuel. Ethanol appears to have been the most successful of those. My 1975 VW Kombi and my 2003 Subaru both run well on current 95 Octane fuel containing 10% to 15% ethanol with no degradation of seals or other components. In fact they run better on that than on normal 91 Octane unleaded, and give matching fuel economy as well.

According to various posts on the Austinsevenfriends site, premium grades of petrol do not (yet) contain ethanol. I have been using this in my 1931 Seven for a couple of years and fitted the push/pull fuel tap with a kit of Viton o-rings and have not had any leaks, not from the tap at least!

Brian