Airhead R100 horrible smoke at cold start

Discussion in 'Airheads' started by More_Miles, Nov 12, 2009.

  1. More_Miles

    More_Miles über-n00b

    Joined:
    Aug 10, 2009
    Oddometer:
    333
    Location:
    New Brunswick Canada
    Nope. On the other hand though, the only time I don't need to use the enricher is when it's warmed up. Current temperatures are such that it need all the help it can get. So this doesn't tell us much... Is it because it's cold or because the enricher is on... Feh...
    #21
  2. Rob Farmer

    Rob Farmer Long timer

    Joined:
    Aug 27, 2002
    Oddometer:
    6,750
    Location:
    Loughborough, Leicestershire. England
    Thats just what mine was like. Mine would be fine for the rest of the day once it cleared.

    You need to pull the heads and barrels and check the bores and rings.
    #22
  3. More_Miles

    More_Miles über-n00b

    Joined:
    Aug 10, 2009
    Oddometer:
    333
    Location:
    New Brunswick Canada
    I'm going to tear into the air box and air tubes tonight when I have it down for fluids change. I'm also going to pick up new plugs, and a compression tester.

    I'll give the rag test a try tonight. As far as the broken ring is concerned, I am hesitant to tear into the cylinder unless I have all the spares there. On the other hand, I'm thinking broken ring = damaged bores = replaced bore = lots of cash... Lets see what we have with the air box....

    Now, memory surfaces, the previous owner told me that the left cylinder "smokes bad when you first start it up in the spring, then doesn't do it again." Now, he was a man in his high 50's who also owned a new R1200RT. He may have also had more sense than I, not riding in these stupid temperatures.
    #23
  4. More_Miles

    More_Miles über-n00b

    Joined:
    Aug 10, 2009
    Oddometer:
    333
    Location:
    New Brunswick Canada
    Perhaps confusing the issue now... Just zipped into town for lunch. Started to smoke when I started it, I killed the enricher and kept it going with careful application of the throttle. The smoke petered out and stopped...

    :huh
    #24
  5. sharkojoints

    sharkojoints is a bit slow sometimes..

    Joined:
    Jul 23, 2009
    Oddometer:
    72
    Location:
    Under a rain cloud, UK
    :1drinkSorry...

    I always suspect and try and rule out the cheapest stuff (ie. rich mixture) first.

    Having said that, Bpeckm's advice sounds about right to me - a compression test would be on my list.
    #25
  6. Mista Vern

    Mista Vern Knows all - tells some.

    Joined:
    Dec 1, 2005
    Oddometer:
    18,809
    Location:
    McMinnville, Oregon
    Not to sound like a broken record (I wonder if that phrase actually means anything these days, as many people have never even seen a record), but all this guessing means nothing until you take that bike out and blow the snot out of it. Then put in fresh plugs and run it hard and then do a plug check. And then do a compression check. Airheads are not fond of cold temps and if the engine hasn't run hard or been well heated up the plugs are bound to look like shit and the vapor is gonna continue to spew out. :deal
    #26
  7. More_Miles

    More_Miles über-n00b

    Joined:
    Aug 10, 2009
    Oddometer:
    333
    Location:
    New Brunswick Canada
    New plugs going in tonight along with fluids change. I'm going to *check* everything here that doesn't require an engine disassembly. I plan on riding as much of tomorrow as possible, so that should count for blowing the snot out of it! :D After this, a compression test. Now, if I can just stop worrying and shut up about it until I get this done! :wink:

    Um, yes, I know what a broken record is.. record is.. record is.. record is.. record is.. ZZZZZZZZZZZZZZIIIIIIIIIIIIIIIIIIIIIIITTTTTTTTTTTT!:lol3 Might have something to do with having a couple hundred in my collection.
    #27
  8. mykill

    mykill odd

    Joined:
    Feb 6, 2008
    Oddometer:
    1,183
    Location:
    Los Angeles
    I'm with Mista Vern. Clean fluids, check and set the basics and ride the crap out of it. I have a Norton that sat for a long time prior to my purchase, an initial compression check had both cylinders below 100#. After a day of riding they bumped up to 135# each. Things get sticky when they sit but you may have corroded rings, most likely the oil control rings. Since it is a Nikasil bike, there is a good chance just the rings are the issue, they are soft and give up to the bores easily. Intake guides are also a possibility, but will be more costly and involved.
    #28
  9. More_Miles

    More_Miles über-n00b

    Joined:
    Aug 10, 2009
    Oddometer:
    333
    Location:
    New Brunswick Canada
    Inmates,

    Well, I tore into the airbox tonight. Guess what I found?

    Oil in the crank case breather tube. Enough that there was a drop or two forming at the end of it. The intake was also oily... I cleaned it all up, and I think I know why the left cylinder was smoking more than the right. The tube that runs from the Tee to the intake was sloped down towards the left. Gravity's a bitch.

    I also took the starter cover off. It looks like there has been some oil getting out into this area. :huh I cleaned it up as best I could, and since I'm almost into the winter cabin fever season, I'll tackle that later. For now, oil is fresh, and I'm going to keep an eye on it. I am pretty sure I know why it's smoking, just need to figure out now why it's blowing oil.

    By the way, new plugs make her start so much nicer. Gapped them, installed them, and Bob's your uncle. By the way, anybody else gap new out of the box plugs? These were 0.030 and 0.035 respectively... Had to go with Autolite equ'vs since nobody in this little burg carries Bosch or the appropriate NGK...

    Edited for stupid spelling mistakes
    #29
  10. Droptarotter

    Droptarotter Long timer

    Joined:
    Jul 11, 2007
    Oddometer:
    1,486
    Location:
    Cloverdale,BC
    Remove your crank case breather and see if it is working.........too much oil might just be getting by the breather.
    That bike should hold 2500cc of oil or 2700cc of oil if you have the oil cooler.
    After the bike has the correct amount in it.......see where it is on the dipstick. The bike might have been overfilled if the correct stick is not in it.
    Cheers
    #30
  11. tennessee thumper

    tennessee thumper Don't Text Me Bro

    Joined:
    Nov 3, 2007
    Oddometer:
    927
    Location:
    Arkansas Ozarks
    I had the smokey start up on my /5. I cleaned out the choke units on each carb and the smoke went away.
    #31
  12. word1

    word1 I'm working on it...

    Joined:
    Jul 24, 2004
    Oddometer:
    511
    Location:
    Rome, GA
    I'm not too surprised cuz that's what I found in my RS (and why I suggested at least looking, back in post 11 :augie). You will find some oil droplets in the breather tube, as a big twin moves a lot of air around in the crankcase.

    When you get around to it again, check out the internals of the crankcase breather. My '78 RS had the older one, which apparently doesn't work as effectively as the new style. The older one is a fibre washer and a coil spring, while the newer one is like a reed valve. My RS puffed quite a bit of oil when warm, and the new style breather virtually stopped it.

    Check an on-line parts fiche (like maxbmwmotorcycles.com) and view section 11, diagram 11_1725. Assembly #2 is the older style, and #3 is the newer replacement part.

    If you have the older one, try upgrading to the new one as it's only $30mumble bucks.

    If you already have the new style (and the diaphragm is intact) then I'll hush and let somebody more experienced speak up :lol3.

    _jay
    #32
  13. fishkens

    fishkens Long timer

    Joined:
    Nov 14, 2009
    Oddometer:
    5,360
    Location:
    Seattle, WA
    A few thoughts:

    The crankcase breather could be a problem (worn reed valve allowing a bit too much venting into the carbs). However, too much oil past the breather could also be caused by more serious problems such as worn rings (compression blowing past the rings, into the case and out the breather).

    When I had worn valve guides on my 78 R100S the most noticeable symptom was smoke on deceleration esp. going downhill (cut the throttle and the piston starts sucking through every possible opening such as the valve guides which sucks oil into the compression chamber).

    Hard tellin', not knowin'. A compression check is step one.

    Keep at it!
    #33
  14. More_Miles

    More_Miles über-n00b

    Joined:
    Aug 10, 2009
    Oddometer:
    333
    Location:
    New Brunswick Canada
    Inmates,

    Post oil change/air filter change/cleaning of the breather system followed by 700 km at or above 110 km/hr (does that count as blowing the snot out of it?) and the bike hasn't acted up since...

    I'm not saying it's cured, since as soon as I do the problem will be back with a vengeance.

    Thanks one and all!

    Cheers!
    Craig
    #34
  15. C Squared

    C Squared Now with TURBO!

    Joined:
    Mar 27, 2008
    Oddometer:
    8,082
    Location:
    FDL WI.
    A compression check will probably not show worn valve guides as the valves will probably still seal on the seats.

    R bikes have guides that have alot of clearance and no valve seals.

    Check into new guides and valves if you find this to be the problem.

    Matt at Motor West in Milw. WI. Sells some "tighter" guides and seals. (high quality)

    I am sure others sell the same ones.

    But give Matt a call.
    #35