Topic: My friend's new old BMW airhead...

[bzr]

...he finally got around to trying to get his dad's bike going. It's a BMW R60/5 toaster tank airhead, with only 9,000 miles on it. It's been sitting in the basement for the past 30 years.

Everything's still there which is great, the fiberglass fenders are flawless, and some of the chrome is still in good nick. No rust at all  on the exhausts, frame, or forks. The plugs are fouled, however, and there's a mysterious rattle emanating from the gas tank. I've shaken it for 5 minutes straight and nothing's fallen out, but when I look inside there's no flaking rust or anything.

I assume that he's going to need a carburetor rebuild to kick things off, and check the compression on both cylinders. What else do you think we should look at (what specific gaskets)? My friend wants to get riding before we both go back to school in late August.

Also, pictures to come Wednesday...

[bucky katt]

check the rear drive unit seal, those are pretty notorious for leaks, i've done a bunch of those but never without the "special" BMW tools. does it have a dipstick or the sightglass on the side of the case?, i dont remember what year they changed from dipstick to sightglass, if it DOES have a sightglass those can be a source for leaks as well. those Bing carburetors can be a chore to get right, but once you do theyre fine.

[tonycb650]

i dont know anything about bmws but does it have some sort of fuel guage? maybe thats what you're hearing in the tank.

[Caminokid]

"special" BMW tools.

My nephew bought a 88 K75S. he was warned at the BMW shop that his bike had to have nothing but the Special BMW tools used on it. I told him they was full of it. I was told by the Snap-On man that if there was these tools...since he sells tools to the BMW shop...he could get them for me. After my nephew dumping almost 10,000.00 in this 2000.00 bike...all cause he listened to the BMW shop.

[mlinder]

The original toolkit, at least on the 75/5, had enough of what was required to do an 85% teardown.
I love those freakin bikes.

Now, I can't remember for sure, but did the tank filler cap have a chain that connected it to the tank so you couldn't lose it? If it did, that's probably it. That's just not somethign I can remember from when I had my slash 5's. slash 5's did not have a fuel gauge, tony, but good idea.

[Tim.]

You should definitely do a spline lube (I have to do mine this fall).  Involves splitting the transmission from the engine by removing the swingarm pivot bolt and pulling the drive assembly back about 1/2 - 1" or so.  Just enough to get in there with some grease.  Then bolt it back up.

And def. lube changes all around.  Engine oil, tranny gear oil, shaft drive oil and final drive oil.  Love my R75/6

[ColinMc]

Don't try and turn it over until after pulling the plugs, putting some oil or marvel mystery oil or something in the cilinders, and kick it over a few times to get things lubed.

My 78 R100/7 has been dead reliable and only has about 30k on it. I think you are on the right track...no idea about the rattle in the tank though.

[phactory]

The rattle in the tank is either a part of the petcock that has come loose or some foreign debris. BMW sells and updated screen/sealing washer that should be used. I would remove the petcocks and flush it out. If there aren't two tubes each on the petcocks then that is most likely your culprit.

Drain all of the oils and in the case of the rear drive/driveshaft, measure the amount of fluid that comes out, against what the manual says should be in there. If that seal is failing oil will migrate from one side to the other.

I would definitely rebuild the carbs as a matter of course and also replace the fuel line, points, condenser, and wires.

 Stone simple and very reliable!

Good luck, Phil

Updated Part #
Has crush washer built in. PN 16121240060 is not needed when purchasing this strainer.