tank removal on a /2

[chwood4]

I have a 1968 R60/US. When I remove the gas tank , in addition to removing the fuel lines to each carb, there is a crossover line at the rear undeerside of the tank. Despite draining as much gas as possible from the tank prior to removing the crossover line, I always end up spilling gas. I've taken to attaching to long pieces of extra fuel line to each side of the crossover, but end up still spilling gas. Does anyone know of any type of fuel line coupler valve I could install in the rear fuel line that would automatically shut off when disconnected?

[DarrylRi]

I actually went so far as to buy a quick disconnect valve that's used on the Oilheads to put in there, but there's not enough room for that.

It's annoying, that's for sure, and I hope I never need to do it on the road.

I ended up cutting up an empty oil bottle to a shape that lets me catch the gas and direct it into a can.

[20774]

The "gas bath" can be minimzed to some degree if you're prepared. I found a rubber cap that fits the tank outlet and just after pulling the fuel line off (and plugging it with my thumb), I can slip on the rubber cap. Then I can deal with the line that my thumb is plugging. Still not fun, though.

[44006]

Park or otherwise situate the motorcycle so that it is
substantially nose down before disconnecting the
crossover and lifting the tank off.

[lbrackr756]

This ain't rocket science. Tank removal is rare so take the low tech approach. Buy a small pair of vice grips, crimp the line under the tank and then remove the line from the side away from the petcock. As you do so, put one finger over the tank outlet to stop any fuel flow. Tilt the tank up (you did remove the mounting bolts and carburetor lines first, right?) and reattach the fuel line over the top of the frame tube. That's it. You might spill all of an ounce of fuel doing this so just keep a rag handy. If the crossover line is long enough you can also tilt the tank up a little bit first to reduce spillage.

Little Egypt Airhead
'66 R50/2
'80 R100RT
'65 Honda 305 Dream (resto project)

[dbrick]

I haven't had a /2 since 1984, but I wonder if there's room (between the tank wings and the frame tubes) to run the side-to-side fuel line *over* the frame tubes, thus allowing tank removal while the line stays in place. If there is room, would fuel remain in the loop when fuel level in the tank is lower than the loop?

[20774]

I haven't had a /2 since 1984, but I wonder if there's room (between the tank wings and the frame tubes) to run the side-to-side fuel line *over* the frame tubes, thus allowing tank removal while the line stays in place. If there is room, would fuel remain in the loop when fuel level in the tank is lower than the loop?

I think this would jeopardize being able to use fuel from the right half of the tank in certain situations. The output spigots for the tank are *below* the backbone of the frame.

[dbrick]

I think this would jeopardize being able to use fuel from the right half of the tank in certain situations. The output spigots for the tank are *below* the backbone of the frame.

I remembered where the spigots are located. I thought that like a siphon, a loop of tubing full of fuel would remain so even when the level in the tank declined.

[20774]

Hmmm...I think that the process is more like air pressure pushing down on each half of the tank. So when the gas is drained from the left half through the petcock, there's less fuel on that side than the right side. The pressure over the two sides plus the extra height of fuel on the right side is going to force the two sides to be roughly equal. That force works pretty well going downward, like into the current crossover tube. But I'm wondering if there's enough force to push the fuel up and over as you suggest. I think it's more a push force rather than a suction or siphoning force.

Seems to me that if that would have worked, BMW might have done something like that in the original design.

I suppose it's worth an experiment. The worst that would happen is that you'd run out of gas...just keep it close to home!!

[dbrick]

Well, my over-the-frame loop may be interesting, but lbrackr756's suggestion is easy and avoids the possibility of air in the loop.

[marchyman]

I'm disappointed that the quick disconnect won't work. I bought a QD maybe 4 or 5 years ago to install the next time I have the tank off. I didn't buy the BMW QD. Maybe mine will fit...if I can remember where I put it... if the tank ever has to come off again. It's been 9 years since the tank was last off.

[BMWDEAN]

Make up a couple of these. Work like a champ. Pull off under-tank hose and immediately attach these to the tank. Never has failed in years.