BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

Hi all --

I have not been active on this site for a couple of years, primarily because I have not ridden my R since it burned out its wire harness. During the interim, I have been having a lot of fun with my Wee Strom, a very capable smaller displacement machine that is reliable and durable to boot (hint BMW . . . ). But I digress.

I am trying to get the R back on the road and have installed a replacement harness that I bought from a someone parting out a wrecked R bike of the same year as mine. I think I've successfully installed the harness, although there is one wire I overlooked and the tag on it has faded to the point that it's not clear to me where it goes (it's brown with a spade lug and I think connects to the oil sending unit). That's not my question though - that has to do with the fuel tank.

The tank has been sitting around for quite a while and I'd like to get all of the old fuel out of it. I just can't seem to though. It won't drain through the lines and I've even opened the filler cap and turned the tank over, which only got a trivial amount of fuel out. How can I drain the tank completely? Or do I even need to bother and can just fill it up, throw some Sea Foam in and not worry?

An unrelated question about clutch line bleeding (as part of the prep to get the R back on the road, I'm renewing all the fluids). I have the bleed nipple that replaces the grub screw but can't seem to get things to work. I see that there is a kind of check valve at the distal end of the bleed line (looks like a ball and socket arrangement) but it's not clear to me how it releases - and I can't remember if there is some kind of trick. It looks like you just screw the nipple down hard but I'm reluctant to use the 1,000 lb/ft of torque it seems to need.

Any and all advice welcome!

Morning, Challey! I don't know how mechanically handy you are, but in my opinion your tank is ready for an overhaul, lol. By this I mean take the flange off under the tank, replace the fuel line hoses, filter and fuel sock inside, probably the vent lines, too.


To do this, you are right you need to get the liquid out if you can still hear it sloshing. I would go somewhere and get a siphon pump of some sort...I have one of these and it is invaluable for almost any fluid task http://www.liquivac.com/


then work all the gas out. I did put B12 Chemtool in the tank before I did this, and sloshed it around good and let it sit for a day or two, then siphoned it out. After you get everything replaced (somewhat specific needs for replacing the hose and clamps, can be found here) I would treat the inside again, because I discovered while working on mine (that sat for a couple of weeks with the flange off) that things can start flaking inside, and your moving the tank around or bumping it can dislodge some particles. After this, I would say you've done due diligence for the tank. I would NOT start it with that old gas in there. Even after you do start it, I would still have a high concentration of some gas treatment in there so it could hopefully clean out the line areas you didn't replace that go into the throttle bodies. I did all this while externalizing my fuel filter so it would be easier to replace in case of plug-up.

In your case if you turned the tank upside down then I agree there is probably a trivial amount in there, but with a siphon can treat the inside, then tilt the tank up on its back edge and using the small siphon hose get just about everything out of there with a little manipulation. Good luck! This site has the info you need to do this, as well as about anything else, lol.

I WISH I had bought a shop manual that would hopefully show the wiring schematic, because some of my wiring projects have been somewhat shade-tree-ish, lol.

I have no advice on the bleeding of the brake fluid, haven't done that myself, yet.

Thanks Rick - I should have mentioned that I replaced the fuel filter just before the bike died. It has less than a couple of hundred miles on it. Even so, while the tank's been off, I took the whole assembly out again and checked the hoses, clamps, etc (an aside: I toyed with the idea of the external filter mod but was talked out if by a long-time BMW mechanic who believes that danger of burst filter overrides the convenience of the external mount). I tried to get the fuel out with the access plate off but again, only got a trivial amount. The tank's insides actually don't look too bad - at least not in comparison to that on my '78 Darmah, which admittedly has been out of action longer.

I'm not sure how much fuel is left in there. I can hear it sloshing but have to think it's probably less than a quart and tucked away in the lower lobes. It does smell nasty though, so I may head to Harbor Freight and buy a cheap siphon and try that.

I recently went through that process. Took the fuel pump plate off the tank and tipped the tank onto its right hand side pooling any remaining fuel just visible inside the flange opening. Few final drops picked up with clean dry shop rag.
Worked great.