Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board Fuel taps 69 Bonnie

So what are the opinions of the fuel taps in reference to the reserve. Changing out my taps and I drained both taps till no fuel came out when removing the tap with the reserve tubing I caught the remaining gas and just shy of one pint was left in the tank. So if you're getting say 50 mpg that pint would get you an extra 61/4 miles. So I plan on cutting copper tube flush and monitor fuel by miles traveled . Just saying that extra gas might be handy sometime.

Here in the desert south west, where it can be a long way between gas stations, I fill up when ever I see one. That quart of gas I just bought just might be enough to get me to the next station. I have never had a speedometer/ odometer that worked.

Hi Jerry, I’ve messed around with this.

From factory reserve tap without stand pipe is on left side. Installing the top as shallow as practical is very slightly helpful.

The right side stand pipe appears to leave a lot fuel in right saddle of tank. Draining tank it kind of does however when riding I don’t know if it’s from vibration or what, but the gas somehow transfers itself to the left.

Running out of gas it looks like too much fuel in right side. But laying bike on left side to get more gas over to reserve tap is only good for a few blocks or so. The bungs are pretty tall in tank. Manufacturers never drain drain tank dry as it can be explosion hazard.

Measuring length of bung & fitting reserve tap in it to get most fuel out is about all we can do.

Running out of gas is interesting. There is zero warning in most cases. It’s like you flipped off key. It sure looks like you have more gas, but the bungs won’t allow accessing it.
Don

If they had fitted a balance pipe then all the fuel could be used but then you would have to drain the tank to remove it.

Dave

Hi, If you put reserve taps in both sides it would be same as balance pipe, since both side hoses go to banjo on carb.

But what I was saying is in my experience the fuel still gets to left side without balance pipe when riding.

A while back I drained tank to derust tank & install liner. With both taps removed there is still a lot of fuel in tank.
Don

Hi, I have reserve taps on both sides of the tank on my '72 Daytona after I found that the location of the spigots on the tank do not give enough clearance for the taps filter before it hits the tunnel of the tank, as the tap is screwed in. This had torn the filter mesh on two taps.

With the reserve taps not having the internal tube inside the mesh filter clearance is less critical, particularly with the Aerco taps, which only have a metal mesh filter without the plastic body. The metal mesh filters are not rigid and just move to the side when they come up against the inside of the tunnel.

Before fitting two reserve taps, I never relied previously on using the reserve fuel anyway, because it is unclear just how much fuel is actually available. Instead, I use the trip counter as a fuel gauge, by setting to zero when filling the tank. When it reaches 100 miles, I know I have at least 20 miles left and think about heading to a gas station. On longer runs, with steady cruising, the fuel consumption improves, but still use my 100 mile rule.

Terry

I thought of that but if you use the pipes to banjo as a balance you still have the fuel in the tank caught below the tall tube on one tap. This fuel can't get to the other side of the tank because of the top frame tube cut out (on a 60s bike, at least). It is like having two fuel tanks.

I suppose it is like having two reserves, however. You run the main tap, then the reserve and then when that has gone you lie the bike over and get the last bit!

Dave

Hi Dave, Yes you are correct with the stand tube on right tap. Once fuel is consumed enough such no more can entertain stand tube, the motor dies. Again nearly instantly. Then you reach down & turn on reserve.

Have you laid the bike over? Was that successful for you?

How much more fuel did you get to left side?

My experience was I only got a few blocks worth of fuel to transfer. My bike will balance on left foot peg to nearly horizontal. I’ll never do it again. Was on grass covered dirt.

I did an experiment. Drained tank from right tap with stand pipe via carb bowl drain. Turned on reserve tap to fill bowl. I started motor & rode around block. Vibration etc. sent some gas into stand pipe. Allowed about 1/8 mile. Motor died. I turned on reserve tap. Bike started right up. Rode a little under 1/8 mile to driveway. Drained tank via bowl drain. I got 1qt. + 1 cup.

I took bike off center stand & jostled bike around. I could see more gas passing through clear fuel filer.
Started motor. I got 4 houses down block & motor died.

Visually it looks like fuel cannot pass to left over the small hump at rear of tank, but that fuel cannot be accessed any way.

40 mpg US is a reasonable safe figure. Riding easy that will give me what. 10-12 miles.

I also use the 100 odometer reading. My trip meter is not reliable. It skips sometimes. My memory skips sometimes. If I’m in unfamiliar area I’ll put masking tape on handlebars & make notes with sharpie pen. I do this often with directions. One route is kissing 140 miles. I think about fuel!! It’s slow country roads so it will just make it before reserve.
Don