Back on an Airhead - 1975 BMW R90/6

Discussion in 'Airheads' started by tete, Aug 27, 2012.

  1. disston

    disston ShadeTreeExpert

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    They sell a small tub of stuff in the auto parts store it is called wheel bearing grease. Sometimes labeled "Disk Brake Wheel Bearing Grease" . Even the most expensive wheel bearing grease is not very expensive. They have the same stuff in motorcycle stores. I think White Lube works but I use Wheel Bearing Grease.

    I have spoke wheels so I can't tell you much about taking the bearings out of those wheels you have. It is best to take the bearing out to clean and grease them. On my spoke wheels I have a special tool to take the large nut off that holds the bearings in place. The bearing races can stay in place on the front wheel but on the rear wheel you probably have to remove the races because you can't get the bearing out with out doing this. I use a torch.
  2. tete

    tete clown shoes

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    Thanks for the response!

    I did a little research and I guess what is needed is to repack the bearings. Now I'm wondering how I can repack them with grease without damaging the wheel. I will post pics in the morning so we can see the difference between what many of u have and mine. The Lester's are not that uncommon so I'm are someone will be able familiar.
  3. chasbmw

    chasbmw Long timer

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    I think that you need to get some advice as to Lester wheels, maybe snow bum has some advice on his site. On my 1975 R90/6 you heat the wheel with a heat gun and tap out boththe bearings as a single stack of parts, if you don't use heat, there is a danger that the bearing outer races will damage the wheels leading to sloppy bearings!

    There is a good chance that the bearings will be OK , once they have been cleaned and regreased, but to do this properly you should remove them. I would replace any grease seals with new, but yet again I don't know if Lester used BMW parts for these.

    you need to be careful with the Lester's, as it would be very expensive to replace them.
  4. craydds

    craydds Long timer

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  5. tete

    tete clown shoes

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    Fantastic article with tons of knowledge. Snowbum recommended. I took me a bit to find this article but made me feel way better about trying to repack them and salvage what I have. Save some
    money without feeling like I'm risking my life.

    Read up and please feel free to chime in.
    Very interesting stuff.

    http://w6rec.com/duane/bmw/wheel_bearing/index.htm
  6. tete

    tete clown shoes

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    I'm wondering if its as simple as removing the Allen head bolts here to access for re packing?
  7. tete

    tete clown shoes

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    How do I Go about adding the krauser cases to these racks? I have a chrome set where the mount is in the proper location. I would prefer the black but there is no holes for mounting the seat belt like bracket accept on top? Which doesn't match the case? !. Confused

    [​IMG]
    [​IMG]
  8. disston

    disston ShadeTreeExpert

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    The part of the black racks that you are thinking is part of a bag mounting system is not the seat belt piece you think it is. That tab on the top of the rack is for mounting a rear rack to, not a bag.

    If you have to have the black racks then find a set of bags that have claw mounts. Like these;

    [​IMG]

    Or you might be able to put these claw pieces on the bags you have. They are still available at your dealer. I think I paid about $36 for one a year ago.

    I think the piece you are missing, the seat belt tang, is still available. Maybe you could have it welded on the the black racks.

    Just so you have all the options then there is one more, paint the chrome racks black. Chrome can be painted with a spray can. Ruff the chrome up some with sandpaper to give the paint something to stick to.
  9. tete

    tete clown shoes

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    Bingo. Ill paint the chrome and put the others for sale in the flea market.
  10. bikerfish

    bikerfish flyfishandride

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    neither of those type of latches should be trusted. see the little gussets on the racks in the corners, they have holes in them about 3/8 in diameter? I line the bag up where it should go on the rack, mark the bag where the hole is,drill a hole in the bag, and use toilet tank mounting bolts to bolt the bag to the rack. the toilet bolts have rubber washers and large metal washers, along with wing nuts to facilitate in taking the bags off if ya want. been running my bags like that for years now, never lost one, same can't be said for some friends of mine that think the latches are all ya need.
    besides, once they are bolted on, the latches aren't even needed.
  11. disston

    disston ShadeTreeExpert

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    bikerfish,

    I thought it was the seat belt latches that were prone to fail, not the claw types? But you're saying my bags are also in danger of being lost?
  12. tete

    tete clown shoes

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    Isn't there like a strap system or suggestion for strapping the bags additionally to the latches ? Also that perhaps has a lock to compensate for the keys nobody seems to have.
  13. chasbmw

    chasbmw Long timer

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    It not just the bags falling off , it's also the door opening for random reasons. A simple luggage strap around the bag and frame is good insurance
  14. disston

    disston ShadeTreeExpert

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    I think somebody might make straps that are sized to fit Airhead bags. There are White straps used when bikes are shipped to the US and these have sometimes been used. You can sometimes get them from a dealer, if they don't just throw them away. The shipping straps are a rather crude material. Some won't like it.
  15. tete

    tete clown shoes

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    Today I went out for a fairly decent ride, about half way through the bike started to smoke from the throttle side exhaust. only this side. This was the first ride of more than 20 miles this winter since it has been wet and busy. ANy how, I notce at higher RPM its worst and most noticeably when stopped. I can rev it up a bit and when I let off the throttle as the RPMs drop it tends to smoke.

    Other than this the bike is running perfect. easy start, no oil light. No hesitation. Of course my first instinct is to think rings .

    Keep in mind that this was the first decent ride since I got her running again this fall. IN which she has been sitting for in a garage for11 years in a AZ.


    please feel free to chime in with you experiences.

    thnks
  16. tete

    tete clown shoes

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    Perhaps I'm not asking the correct question. Other than the rings, what perhaps could cause the smoke from the right exhaust. More specifically at Highr rpm and when letting off the throttle. Please advise. I'm loosing some serious sleep about this.\
    ---------------------------------------------Hours later Edit----------------------------------------------------

    So i started going through as many threads as possible to help with this smoke issue.. I curently don't have any tools to measure compression and won't have any new tools for a while because I am broke. I just barely got enough cash to put on new tires.

    Moving right along I saw that in many instances its the left cyclinder that generally shows signs of smoke.. however this really means nothing.

    I did notice a few post in which many indicated that the breather system dumps into the right cylinder or something of the sort. And the turkey noise as well. Well it happens that Before my ride today my buddy and I - airhead airheads- were talking about how our bikes make that weird turkey gobble sound for lack of better desciption. anyone care to elaborate on this? My bike feels and runs like a champ, starts with ease etc.. no oil light on etc.. tends to smoke when I let off the throttle from higher than 4k rpm. at low RPMs seems to be ok.

    sorry about my grammer.
  17. disston

    disston ShadeTreeExpert

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    It may be a problem with the Turkey Valve. It is the engine breather system. Continue reading what ever you can find about this, both here and on the web. I can't tell you it is the Turkey Valve, would be nice if it was is all I know.

    Are you using 20w-50 oil? We won't go into what oil or what additives, API rating, or anything else. If you are running 10w-40 because it is Winter then I suggest you start running 20w-50. This may cut down on the smoke while you are taking care of the problem.

    How many miles on this bike? How many miles since new rings, rebuilt heads, or any major engine work?

    You will need $100 for gaskets and parts to remove the heads, $500 for rebuilding cylinder heads and more money for piston/rings work but can't say what you need till it is apart and measured.
  18. tete

    tete clown shoes

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    Damn. the bike has 96k miles. I don't have any history of work on the bike. It sat for ten years in wealthy mans garage. I bought it from his son when he passed. I got it running with your help more so than anyone else's. which I greatly appreciate still. Regardless I will try everything first, if that means running 20-50w and figuring out the turkey valve thing first. Is the valve accessible w/o removing te jug head assembly?
  19. disston

    disston ShadeTreeExpert

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    Yes Tete, I remember when you got this bike. I don't remember all the details but I do remember you've been one of the best students I've ever known. Unlike many we see here you have the guts to hang with it. It's not easy I know.

    At any where from 90K to 120K these bikes are well worn and many of them are in need of extensive rebuilding. There's a guy here with 250K on an original Airhead motor and everybody else thinks they will do the same. Thatr is rare. It's so rare I actually don't believe him. I'm not calling him a lier but it's either that or he has made a mistake in his records.

    Start running BMW Brand 20W-50 Dinosaur (not Synthetic) motor oil. Do not even think about the promises of a New World Order where machines run forever on piss made by the Gods of Capitalism. If you can't get BMW brand motor oil, usually only available at BMW dealers, then use Spectro (they make BMW oil).

    I think you should buy a compression gauge. Get a used one from Ebay. I bought one 6 months ago for less than $20. One of the cheaper push in types work fine on Airheads, the screw in type are more expensive and if you are buying used the threads may be messed up.

    Here is what looks like a good deal. It also has screw in but it has push in. If any of the adapters are messed up they may be available. The rubber tips look good. And it has the original box.

    http://www.ebay.com/itm/Compression..._Automotive_Tools&hash=item19d86dad7d&vxp=mtr

    Start saving your nickles and dimes. These are great bikes and they are usually cheap to start with but they will need work to keep running. Most of us have much more into these bikes than they are worth.
  20. disston

    disston ShadeTreeExpert

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    If you buy a push in type compression tester used beware of worn out rubber tips. They will sometimes still work but you can't tell. So don't get any that have a bad picture or a worn out tip. the bad picture is to hide the fact the tip is worn out. You can buy the tips sometimes but they will cost more than the whole tool.
    [​IMG]

    This is a really old one. It may still work but the tip is worn out.