Airhead "Tips and Tricks"

Discussion in 'Airheads' started by elmoreman, Sep 26, 2006.

  1. datchew

    datchew Don't buy from Brad

    Aug 1, 2005
    Remember the Alamo!

    Here's more than you wanted to know about coils:

    And here's some starter info:
  2. RandyB

    RandyB .

    Jan 11, 2006
    A cheap helmet lock can be found anywhere they sell guns. Ask the counterman for the cable lock that is shipped with every new gun. They'll usually give them away. Thread it through something on the bike and the d ring or face plate of the helmet. They're usually plastic covered so no scratching.
  3. Lornce

    Lornce Lost In Place

    Aug 17, 2003
    Way Out There.
    This is a handy method to set your ignition timing that can be done in about 5 minutes, anywhere. Even on the side of the road if you have to.

    1. Remove both spark plugs and lay them on the cylinder heads attached to the high tension leads.

    2. Remove the front engine/timing cover.

    3. Use something plyable to stick in between and splay the ignition advance weights to their maximum fully advanced position (piece of old fuel line, pencil eraser, whatever).

    4. With the ignition turned on and turning the engine slowy over by hand using a 6mm allen key in the nose of the crank, watch for the fully advanced timing mark (F) through the hole in the bell housing while you listen for the crackle of the firing spark plugs.

    5. Adjust the trigger plate/points plate until you achieve a perfect straight on F mark plug crackle.

    6. Continue riding on to Bangalore or Santiago or Chengdu or wherever you were going on your cool, old, self-sufficient /5/6 or /7.

    you're welcome,
    Lornce :norton

    Attached Files:

  4. notarex

    notarex Can U taste the waste?

    Sep 12, 2006
  5. face scrape 2001

    face scrape 2001 avatar of Nullarbor graffiti

    Feb 16, 2007
    Adelaide Hills South Australia
    G'day Lornce, why would you want that rubbish, it is just that. Do you want to appraise it for a survey? I'll take a pic of it, I still have it in the shed to show other people after fifteen years, if you really want?:ear
  6. Beemerboff

    Beemerboff Long timer

    May 23, 2005
    Adelaide, South Australia
    To answer the question on Dyna coil, the answer is a definetly yes.

    Buy it from Rick at Motterad Electrik and he supplies a bracket that mounts in the stock location, and the correct terminals so the coil fits and the wires push straight on, no drilling , grinding or new terminals needed.

    According to the English ignition maker Boyer , the Dyna coils are the best they have tested .

    I fitted one at the weekend to replace the 14 year old OEM on my R100GS which I suspected was on the way out, and was rewarded with an immediate improvement in starting , it has also smoothed out a rough spot I had between 2900 -3300RPM in top gear and the engine feels livelier throughout the rev range - excatly the same as when I fitted one to a R75/7 a few years ago.:thumbup
  7. Lornce

    Lornce Lost In Place

    Aug 17, 2003
    Way Out There.
    Nowt wrong wi K&N's maite.

    Prop'ly cleaned an oiled they'll stop whatevah's comin yah motah's why.

    Bin usin'em fer'revah wi no plans ta stop now.

  8. Sancho Panza

    Sancho Panza Super Black Eagle

    May 11, 2007
    Jackson, WY
    I may be buying a low mileage R100RS, it has been inside all its life, it's been serviced every year but hasn't been ridden much. Am I insane to buy this bike, it looks good runs well but I'm concerned I'll be buying a headache. What should I check out before I buy it, splines, carbs, rubber, etc., etc. HELP!!!
  9. woodgrain

    woodgrain In-Dented Savant

    Jan 29, 2006
    east of Scarbaria
    I have several airheads, and yes they require love and attention once in awhile, but so does everything else I've ridden. Advil is available at your local pharmacy.

  10. elmoreman

    elmoreman takin' a break, boss

    Jul 1, 2005
    Elmore, VT
    Who "serviced" it every year? R100RS is a very desireable bike, considered by many to be one of the best sport-tourers. If it runs well, the carbs should be ok, you can look at the rubber and check it for cracks, etc., and if it is low mileage the splines will likely be fine. I'd take some pics and post them in a separate thread here. You'll get more responses that way.

    You should be prepared for regular maintenance anyway, parts are readily available both new and used (although the prices for parts are steadily increasing), and the bike should last a long, long time.
  11. Lornce

    Lornce Lost In Place

    Aug 17, 2003
    Way Out There.
    A low mile '84 R100RS is a pretty safe bet.

    Nikasil bores mean that all those years of storage haven't corroded the iron bores (there aren't any).

    Low mileage should mean rear wheel drive splines are in very good repair. In fact, post '81 twin shock airheads use a cush dampened driveshaft that all but eliminates drive spline wear/damage if they're kept properly lubed. IF properly lubed.

    Change all the fluids (forks, motor, trans, driveshaft, rear drive housing) and go through the bike cleaning all the electrical connector contact points (the cause of MOST of the service issues you'll have with a bike like this). Dissassemble and clean the carburetors and inspect the rubber diaphrams.

    Think aobut fitting modern shocks: Works Performance work well and are priced reasonably. A Corbin seat is a nice addition, too.

    With a clean bill of health the bike should be good for some travel. These are great motorcycles for serious distance riding/traveling. Smooth, effeicient, comfortable, quiet and fast.

    bon voyage,
  12. RandyB

    RandyB .

    Jan 11, 2006
    Here's one I had forgotten: I drop the main jet holders every other oil change (~6-8K) and blow out all the oil/gas mix that accumulates there as a result of the crankcase breather. It keeps the mix even on both sides and seems to eliminate those pesky vibrations that seem to come from nowhere. Way easier than the endless carb synch drill.
  13. Beemerboff

    Beemerboff Long timer

    May 23, 2005
    Adelaide, South Australia
    You can reach this area by blowing carb cleaner down the larger of the two holes that run parralel to the intake - the cleaner should come out freely round the neele jet.
    If you spray in the smaller hole ir should come out of one of the pinpricks downstream of the butterfly.
  14. MrLuftkoph

    MrLuftkoph n00b

    Jun 28, 2006
    FWIW there are a lot of 'right' ways to substitute the standard BMW
    soft rivets, but more wrong ways I suspect. The way I've documented here works, but so do many other methods. Aircraft quality high strength rivets are plenty strong in shear for example, and could be used successfully...if you have a riveter that can handle them....:) Make sure your joint is tight in shear, and you are probably good to go.

    Here is what I did, and why.

    Thought you'd all be interested, and others I've sent this too thought
    I should post here goes. I've done a lot of work on this.

    First of all, the rivets are mild steel. The steel rivets used in our
    wheels work under shear, what I mean by that is they stop the hub from
    rotating because of the tight fit they have to the holes in the hub
    and female spline. These rivets are 'cold' upset, i.e. the heads are
    peened over with a cold rivet. They don't really clamp the hub to the
    spline as bolts are normally used to do, or as 'hot' rivets do on say
    an old bridge.

    Both the holes in the spline and the holes in the hub should be almost
    exactly .250 inches. I have a rivet from my drive in front of me and
    it measures 0.249" for the part that was in the aluminum to 0.247 for
    the part that was in the steel hub.

    If you are going to bolt the hub you can get the best of both worlds;
    i.e. a tight shear load fit of bolt to hole, and a good clamping
    force. Most people use socket head screws and 'clamp' the 2 parts
    together. The friction between the 2 parts is what stops them
    slipping, not the tight fit of the sheer load.

    Now, some people just use Stainless Allen bolts instead of close
    tolerance ones and they claim this is foolproof. I bet it does work
    fine as they are adding a clamping force to compensate for a possible
    (if the shank diameter is at the small end of the tolerance) lower
    sheer loading ability. If the fit is tight they would work fine.

    But I figure the original BMW designer used shear loading for their
    design so I know it works, and using a shear loaded fastener of equal
    or better strength and adding a clamping force only makes the joint
    stronger. The problem with standard fasteners is that the shank
    tolerance is 0.242-0.249 usually.....a big tolerance for a sheer fit
    fastener and generally not acceptable when at the low range. We want
    a very tight fit of the fastener to the hole for a proper sheer
    fastener. If you are lucky you may find 0.249 standard
    fasteners...but I couldn't find any. So the fit was loose. I went to
    MIL spec...see below.

    Basically you want a 'close tolerance' bolt, or one that has an
    unthreaded portion of the shank at 0.2485-0.2495 in diameter. You
    don't want any of the threaded portion of the bolt in the holes. If
    threads are in contact with the aluminum it will act like a saw and
    machine its way through your hub....ouch.
    - Use hardened washers under the nut.
    - machine(I needed to use a carbide cutter in a lathe, any machine
    shop can do this for you)/file the new spline hub so that the surface
    where the nut is going is parallel to the mating surface of the hub.
    There should be enough clearance for the nut to rotate on the bolt.
    Failure to do this will cause the bolt to fatigue and loosen as the
    surface is curved right now. Also the carbide cutters leave a radiused
    'corner' so as to minimize stress concentrations. Don't remove any
    more material than you have to.
    - degrease/clean the mating surfaces, remove all oils etc.
    - bolt the hubs together. You may have to ream a few holes out with a
    0.25" hand reamer to get everything lined up, but I did not. I did
    have to use a soft faced mallet to tap some bolts in place as they
    were a tight fit. This is good and ensures a good sheer fit. The
    bolts come from the outside of the hub. I had to very lightly chamfer
    the hole on the outside of the aluminum hub so as to give clearance
    for the radiused portion of the bolt head where it joins the shank.
    Failure to do so will leave a gap between the head and hub potentially
    and could cause the hub to become loose eventually. Make sure there
    are no gaps.
    - torque and I would also use loctite red or blue...your choice (The
    nuts are self locking though). I torqued to 13ft/lbs. I would have
    used 15 ft/lbs but as the threads are wet from loctite I reduced it a
    - I then used a small diamond wheel in a Dremel tool to cut off the
    protruding threads of the bolt so they did not interfere with the rear

    Now, if your holes are elongated, all is not lost. You could most
    likely move up to the next size fastener and drill and ream the holes
    in the hub and splines to match. A lot cheaper than a new hub.

    I had to very lightly chamfer the hole on the outside of the aluminum
    hub so as to give clearance for the radiused portion of the bolt head
    where it joins the shank. Failure to do so will leave a gap between
    the head and hub potentially and could cause the hub to become loose
    eventually. Make sure there are no gaps.

    As mentioned earlier, for the bolt you need unthreaded shank in the
    holes, + the thickness of a washer under the nut. The unthreaded
    portion or shank length should be ~.675" + 1x the washer thickness
    (I'd measure your own hub and driven spline cup to compare). You can
    always stack washers as spacers if you want. Basically you want no
    threads in the hub or spline cup.

    I used MIL spec bolts, nuts and washers.

    Here are the part numbers I used:

    MS21250-04012 (12 point close tolerance bolts, cad plated)
    MS20002C4 (washers, countersunk on one side as the bolts are
    radiused under the heads, you will also need to grind one side so as
    to fit this under the nut on the spline cup.)
    MS21042-04 (self locking nuts)

    All of this stuff is for 1/4-28 thread size.

    I have my hub together, so if you want I can take some pics for you.
    I haven't used it though, but it is properly designed and I believe
    this is better than original. BMW couldn't afford to do this as these
    fasteners cost me ~$3 each.

    Just so you know, there are other options. Aircraft AN-174-12 will
    probably work as will NAS 6204-13 for bolts. If you have an aircraft
    supply place they can help you out. Check head diameters and
    clearances on the hub though.....

    Also, if you know anyone that manufactures aircraft, there are some
    VERY strong blind rivets out there, that equal or exceed that of the
    steel rivet (it's about ~2,000lbs shear I think, my data is at home).

    BTW, I can back all of this up with engineering books. Carroll Smith
    has a great one on fasteners for racing. I'm a techno geek so I love
    books like this...(my wife thinks I'm crazy)

    NOTE: ALL FASTENERS ARE NOT EQUAL. I hate using bold typeface, but
    if you substitute full thread fasteners, loose fasteners, ungraded
    fasteners, etc. there is a good chance that your hub will fail! Clean
    the mating surfaces, torque everything properly, machine the hub
    surfaces and everything will be done in a proper way. Fasteners
    differ in many regards, not only in strength or corrosion resistance.

  15. R-dubb

    R-dubb Dubbious Adventurer

    Aug 4, 2001
    San Francisco
    Good advice :deal
  16. Scootertrash58

    Scootertrash58 Trust not your leaders

    May 5, 2006
    SouthCarolina, Backroad Barnstormer
    1. My personal tip/trick for all the Bing carb issues that show up in every airhead forum is Mikuni. Instant throttle response, set-em-and-forget-em reliability and at least a small boost in gas mileage. Rocky Point Cycle has them. Pricey, but absolute reliability.
    2. As to the K&N issue, I bought one 9 years ago, I follow the cleaning/oiling procedure, I got no complaints.
    3. Batteries? I got one of those Omega(?) batteries on ebay($50?) about 6 years ago, never had to charge it, it gets washed off twice a year whether it needs it or not.
    TIP TO NEW GUYS: Use GL-4 rated synthetic gear oil in your tranny. The transmission is the weakest point in these otherwise bulletproof motorcycles. Personally, I use Royal Purple 75w140 MaxGear.

    Ride Long, Ride Safe :super
  17. kbasa

    kbasa It's good to think. Super Moderator

    May 28, 2002
    Marin County, California
    The 83 and 84 model years are notorious for valve recession issues. You'll wind up doing a top end on it, unless someone has already done them.

    Watch for rapidly shrinking valve clearances as the indicator it's time to pull the heads and get them done.
  18. Swegen

    Swegen BMW student

    Jan 15, 2004
    Schaumburg Illinois
    Had a strange "chuffing" noise while idling. Thought it was a bad vacuum hose and decided to just get rid of all the emissions plumbing. Maybe old news to some folks but a revelation to me, the ports in the engine for the emissions plumbing are 16mm x 2 = Universal auto oilpan drain plug for $1.50 :clap . Had to saw the plug shorter but it is the right thread to get the job done. Probly spent <$5 all together. Not to mention the newly acquired '89R100GS sounds MUCH better and runs smoother-stronger!
  19. petefromberkeley

    petefromberkeley -

    May 13, 2004
    Berkeley, CA

    I wrap that boot with electrical tape even if it is brand new. Why take chances? And you dont even realy see the electrical tape if you do a neat job.
  20. petefromberkeley

    petefromberkeley -

    May 13, 2004
    Berkeley, CA
    I remove it at the battery and if I need to keep cutting power, I use my vice grips to clip it on and off the battery terminal as needed. Of course you wouldn't clamp down hard on it, just enough (since battery terminals can break)