Carb adjustments for trail riding, TLR200

Discussion in 'Trials' started by Irish John, Jun 3, 2013.

  1. Irish John

    Irish John Been here awhile

    Joined:
    Mar 30, 2008
    Oddometer:
    235
    Location:
    Lawrence, KS but I'd rather be in Ireland
    Planning to take my new TLR200 to Colorado for a little trail riding in a couple weeks. Going from the Flinthills of Kansas to elevations of 6000-9000 ft. Suggestions for carb adjustments?
    #1
  2. lineaway

    lineaway Long timer

    Joined:
    Oct 1, 2011
    Oddometer:
    3,352
    Location:
    nm
    There was a couple of threads on here and trials central. The stock carb came lean. The pilot and main jet need to go up several sizes. Pilot 40+ (hard to find, I drilled mine) main I think 100. Air box needs to breath better. All I did was remove snorkel. Somebody else will be along shortly to reverse what I say. The thread on trials central was more detailed if I remember right
    #2
  3. Twin-shocker

    Twin-shocker Long timer

    Joined:
    Jan 28, 2012
    Oddometer:
    1,673
    Running a carburetor equipped bike at altitude will mean reducing the size of the jets, as air molecules are less dense at high altitude, and the amount of fuel most be reduced with that in mind.

    This site provides some useful basic info on carb set up, which seems to me an awful lot more accurate than the type of thing that gets posted up on chat forums: http://www.iwt.com.au/mikunicarb.htm
    #3
  4. lineaway

    lineaway Long timer

    Joined:
    Oct 1, 2011
    Oddometer:
    3,352
    Location:
    nm
    As usual someone riding at sea level giving jetting advice. I live at 6500ft and ride from that to 9000ft. Your turn Brewtus!
    #4
  5. Brewtus

    Brewtus Buffoonery, Inc.

    Joined:
    Jul 30, 2008
    Oddometer:
    3,228
    Location:
    Albuquerque, New Mexico

    Okay. Here goes.




    Brilliant. Yet another response from a Troll who as far as I can tell has no real-world experience, yet enjoys telling others how to do it. With a theoretical jetting link (accurate, but theoretical nonetheless) for Mikuni carbs when the TLR came with Keihin carbs. What's the matter, did it get cold in the shadow of your keyboard and you came out spouting your usual surface knowledge nonsense to get warm?? A great link to TLR jetting can be found here, a big thanks to Taxonomy for the info :clap -

    http://www.advrider.com/forums/showpost.php?p=18201544&postcount=1

    Twintroller you can argue with me all you like, I really don't care. We both know what you are. All of us who actually work on bikes do. Irish John, have fun with your 'Flex, and sorry about the hijack. Brewtus out. :D
    #5
  6. laser17

    laser17 Been here awhile

    Joined:
    Mar 6, 2008
    Oddometer:
    957
    Location:
    Boston,Massachusetts
    Lineaway - your clairvoyant!

    I remember the 1st time my dad re-jetted my bike for altitude and being very, very confused when the move to a richer pilot helped alot.
    #6
  7. lineaway

    lineaway Long timer

    Joined:
    Oct 1, 2011
    Oddometer:
    3,352
    Location:
    nm
    Yes altitude is quite amazing. I was talking to our ex champ rider (B.S.) about the hard time we had jetting our bikes for over 12000ft plus at ttc. We had started the same minute at the `74 ute cup.
    Some knowledge verses real world experience is quite the opposite at times!
    So I just grin and bear it when someone intelligent comes along!
    #7
  8. Old Geezer

    Old Geezer Been here awhile

    Joined:
    Nov 15, 2012
    Oddometer:
    187
    Location:
    New Mexico
    Brewtus, do you have a new email address? If so PM me.
    #8
  9. Brewtus

    Brewtus Buffoonery, Inc.

    Joined:
    Jul 30, 2008
    Oddometer:
    3,228
    Location:
    Albuquerque, New Mexico
    PM sent.

    BTW, when are you gonna let us ride that Whitehawk? :evil
    #9
  10. Old Geezer

    Old Geezer Been here awhile

    Joined:
    Nov 15, 2012
    Oddometer:
    187
    Location:
    New Mexico
    Just as soon as I get a tank for it. The guy has had the old one as a sample to build a new alloy tank for over a year. Last word (before Xmas) was all he needed to do was polish it, maybe next Xmas. :(
    #10
  11. Irish John

    Irish John Been here awhile

    Joined:
    Mar 30, 2008
    Oddometer:
    235
    Location:
    Lawrence, KS but I'd rather be in Ireland
    I appreciate the link and advice. In checking with my Honda dealer, the#40 jet isn't available. Other suggestions?
    #11
  12. lineaway

    lineaway Long timer

    Joined:
    Oct 1, 2011
    Oddometer:
    3,352
    Location:
    nm
    99124-076-0400 did you try this part number or just asked the dealer? (Which only punches into the computer like a zombie with no mind) I also said the jet was hard to find. Drilled mine. You can always buy a carb.
    #12
  13. lineaway

    lineaway Long timer

    Joined:
    Oct 1, 2011
    Oddometer:
    3,352
    Location:
    nm
  14. lineaway

    lineaway Long timer

    Joined:
    Oct 1, 2011
    Oddometer:
    3,352
    Location:
    nm
    That was 4 minutes too long.
    #14
  15. UtahGuido

    UtahGuido Long timer

    Joined:
    Nov 29, 2007
    Oddometer:
    5,244
    Location:
    Spine 'O the Wasatch
    I'm at 7000 ft and mine runs rich. In fact the spark plug is so sooty I don't even know how it runs as well as it does. The jets might be stock, I suspect they are, but I don't know. I pulled the snorkel but all that did was make it so I have to use a bit of choke to start it. Was rich before, is rich now.

    So I'm thinking that if mine is this rich but seems to run okay maybe you don't need to change the jets at all Irish John. Maybe just forget about it and don't look at the spark plug.
    #15
  16. lineaway

    lineaway Long timer

    Joined:
    Oct 1, 2011
    Oddometer:
    3,352
    Location:
    nm
    #16
  17. UtahGuido

    UtahGuido Long timer

    Joined:
    Nov 29, 2007
    Oddometer:
    5,244
    Location:
    Spine 'O the Wasatch
    I've read about these adjustable cam sprockets elsewhere. I think I'll have to get me one. And I seem to recall some advice (probably from my friend Tom, my guru for things engine - most of the time) about advancing timing one degree per 1000' elevation. That would make sense given Brewtus' results.

    So you think if I advanced the timing my sootiness would go away, or at least diminish, short of rejetting? Sorry IJ, don't mean to hijack the thread.
    #17
  18. Irish John

    Irish John Been here awhile

    Joined:
    Mar 30, 2008
    Oddometer:
    235
    Location:
    Lawrence, KS but I'd rather be in Ireland
    Hmmm, seems to be several schools of thought here. As I won't riding at elevation all the time, the idea of the adjustable cam sprocket is probably not worth the effort. As the engine will run lean at higher elevation from thinner air, could I increase the air flow by removing the snorkel on the air box? Don't think I want to switch carbs. When I checked the part number for the pilot jet with my dealer, it came back as no longer available. As most of my riding is at lower elevation, won't drilling the existing jet to a larger size effect performance when I come back to lower elevation?
    #18
  19. Twin-shocker

    Twin-shocker Long timer

    Joined:
    Jan 28, 2012
    Oddometer:
    1,673

    If you feel that the laws of physics can be altered to suggest rubbish posted here which suggests bigger jets are required for proper running at higher altitude is in fact correct, it would seem not only are you a troll but a pretty stupid one at that!

    Here is another link that provides rather more accurate information than that issuing from under the bridge: http://www.4strokes.com/tech/howtojet.asp
    #19
  20. Twin-shocker

    Twin-shocker Long timer

    Joined:
    Jan 28, 2012
    Oddometer:
    1,673
    A motor will run rich at higher altitudes with sea level jetting, as the air density reduces as altitude increases, and the amount of fuel must then be reduced to compensate for lower air density.

    Removing the intake silencer on a TLR doesnt do very much at all (at least according to a dyno), but removing the flame trap and running a foam pod type filter inside the stock air box, will improve things quite a bit (and does make a difference to dyno readings).

    In the world of the net chat forum though, its very easy to rewrite the laws of physics, and to claim that you need to fit bigger jets to compensate for thinner air at high altitude, which will mean bikes running far too rich, and may result in engine damage on 4T motors.
    #20