KLR250 thread

Discussion in 'Thumpers' started by Bad Company, May 10, 2008.

  1. RebelYell

    RebelYell Been here awhile

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    The carb needs a good cleaning,all the pilot and main jet holes are probably clogged up from the damn ethanol corrossion.This gas dont even least 3 weeks before it fubars everything up.The breather puking problem could be the bike is overfilled w oil,bad rings to maybe the carb being clogged.usually something pressurizes the crankcase to squirt oil out.I'd adjust the valves as well.Its not an old machine but I guess depending on how one took care of it,that doesnt mean squatilla half the time.Good luck w your bike.
  2. MrBob

    MrBob Certified Geezer

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    Ordered the sheepskin seat pad last Friday and it was on my doorstep here in Colorado today :eek1
    How do they do that?
    After an hour of riding on and off road the sheepskin didn't noticeably make sitting on the KLR seat any more bearable. I pulled the seat and the vinyl seat cover and got ready to do some carving in the foam. That's when I discovered that rather than foam, the seat innards are gel. Good luck cutting that. Besides being hard, gel reaches very high temps when left in the sun and hold those temps for a long time. The gel in my bicycle seat got hot enough to split the cover.
    So, I need to choose another seat.
  3. 8gv

    8gv Long timer

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    You need to check for mouse nests and grain stores. A bike sitting that long can have some interesting additions from Mickey. Pull out the air cleaner and remove the snorkel. Look around with a flashlight. Pull the spark arrester from the exhaust and look in there to. Or... You can just fire her up and smell the popcorn!:lol3
  4. MrBob

    MrBob Certified Geezer

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    I've been wanting to shorten the kickstand and kickstart on my 250 so today I pulled them from the bike and headed off to the welding shop.
    Because the seat height is a little high for me getting on and off the bike is awkward with the stock kickstand.

    [​IMG]

    A little hacksaw work and it's an inch shorter...

    [​IMG]

    After carrying off the angles and re-welding the pad in place the kickstand gets two coats of paint. This was my first ever practical weld outside of class and it turned out okay. Don't ask me how much grinding it to took to make the weld look presentable.

    [​IMG]

    Next post, the kickstart.
  5. MrBob

    MrBob Certified Geezer

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    I found it awkward to raise my leg high enough to engage the stock kickstarter.

    [​IMG]

    After clamping the arm in a vice I gradually began to heat it with the torch after cutting off the portion that supports the foot. Two bends were required: one 90 degree bend and a slight bend to line it up with the engine. This is the final result before two coats of paint were applied.

    [​IMG]

    The kickstarter is about 4 inches shorter now. This modification works because the engine is relatively low compression and doesn't need much push to kick it over.
    Tomorrow, the paint is dry and the parts are reinstalled.
  6. Fire Escape

    Fire Escape Long timer

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    I can see where each of those mods would be an improvement. While I can and (occasionally) do weld, I went for more expedient ways to deal with those items. For the stand, rather than go to the effort of shortening it I just ground a little (doesn't take much) off the 'stop' so that it could rotate just a touch further forward and the bike would then lean over far enough that I dared walk away from it. For me (at the time) it wasn't so much the height of the kick start lever that was an issue, more the fact that at the bottom of the stroke I would bash my foot against the footpeg. Even wearing full on moto boots it would hurt so I just heated and 'reshaped' it to move my foot just outside the peg. These days, the shortening of the lever so I don't have to get my foot so high sounds pretty appealing. I might have to revisit that one. Thanks!
    :clap


    Bruce
  7. XDragRacer

    XDragRacer Long timer

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    Corrected!
    Not that hard for me, but . . . then, I'm left-handed!

    Try this: Rotate your right foot in a clockwise circle; with your right hand, make the figure "6" in the air . . .

    (BACKWARDS, mirror-image sixes don't count!)
  8. MrBob

    MrBob Certified Geezer

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    [​IMG]
    [​IMG]

    I have a 30" inseam. With the sidestand 1" shorter it's much easier for me to get on and off the bike. Now, I can brace my hands on the bars when dismounting. This mod gets and 9 out of 10.

    [​IMG]
    [​IMG]

    In spite of it being several inches shorter it doesn't feel as if the kickstart arm requires noticeably more effort when starting. The bike started second kick today, about 6 fewer than usual on a cold engine. It's also much easier for me to get my leg up high enough to engage the kicker.
    But, at the bottom of the kick my toes hit the peg. If I turn my foot outward, I clear it. I'll need to live with this mod for a while before making up my mind and I'll also try tilting it further forward, but for now, 5 out of 10 points.
    Lessee, how am I doing besides the above mod: Front brake rebuild - excellent. Sheepskin - returned. Uni filter - who knows? LED tail light - Excellent. Kenda 207's - Excellent. Rejuvenating ugly green plastic with heat and sanding - Meh. Coming soon: Seat Concepts seat pad and Sigma6 jetting system.
    Hope this helps you when messing with your bike.
  9. bohntr

    bohntr n00b

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    I am having problems with oil getting into my air box and I heard about putting a pcv valve on the crank case vent, does anyone know what pcv valve I should use or does it not matter?
  10. XDragRacer

    XDragRacer Long timer

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    From tests on KLR650's, the crankcase remains at positive pressure during normal engine operation at all rpm.

    Thus, the function of a passive valve, as in PCV valve so installed (or the vaunted Mercedes reed valve), appears questionable at best.

    Yet, TRUE BELIVERS insist a PCV valve installed in the crankcase breather hose produces additional power, greater fuel mileage, enhanced engine compression braking, better ring seating, AND lower oil consumption.

    The function, if any, of a PCV valve in the crankcase vent line, vented to essentially atmospheric pressure of the air box, must be quite different from an automobile PCV valve, connected to the intake manifold and metered by intake vacuum.

    I've yet to encounter a plausible explanation of how a PCV valve in the crankcase vent line performs it wonders, but--that doesn't mean the claimed benefits are not genuine (although inexplicable and unmeasurable).
  11. Tsotsie

    Tsotsie Semi-reformed Tsotsi

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    A PVC (one way valve) valve will not work due to the excessive crankcase pressure being created. Address the cause - probably excessive piston blow by passed the rings. That would contine with a one way valve.
  12. truck6driver

    truck6driver The Fireman

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    P. C. V. Valve: Positive Crancase Ventilation valve

    Valve is closed until the valve's rated pressure is reached to open the valve. Automotive valves do have different pressure ratings so do your research well.
    The idea is that by keeping the correct pressure in the crankcase will aid in piston movement. With a slight amount of positive pressure in the crankcase it helps the piston move up, by putting pressure on the bottom of the piston during the up stroke, thus making the engine more efficent.
    Without it when the piston goes up it will have a negative pressure in the case pulling the air back in slowing the piston when it goes up.

    Will it work on the KLR I have no idea.

    If you are getting oil in the air box I would try a long hose run high as straight up as possible then to the air box. This will allow the excess oil to run back into the crankcase and not into the air box.

    Ray
  13. MrBob

    MrBob Certified Geezer

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    Have you done a leakdown test?
  14. XDragRacer

    XDragRacer Long timer

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    From "How Stuff Works," Wikipedia, etc., automotive PCV valves are continuously open when the engine is running EXCEPT when extreme overpressure occurs from an intake backfire. The middle letter, "V," for "Ventilation," indicates an automobile PCV's function: Ventillation of crankcase gasses and aerosols to the INTAKE MANIFOLD (by contrast, the KLR PCV valve mod is connected to the essentially atmospheric pressure of the airbox, no vacuum modulation in play).

    Intake manifold vacuum regulates PCV valve flow rate on an automobile; most restrictive at maximum vacuum (e.g., idle, decleration), and least restrictive at lowest vacuum (e.g., acceleration, WOT). With no intake vacuum modulation on a KLR PCV valve mod, wouldn't a passive, one-way PCV valve in the crankcase vent hose simply open (from the continuous crankcase overpressure found in a running engine), venting into the airbox?
    If positive crankcase pressure forces the piston up, wouldn't the piston have to OVERCOME that positive pressure on the downstroke, resulting in a WASH (with slight adiabatic/thermal hysteresis losses) as far as efficiency is concerned?
  15. truck6driver

    truck6driver The Fireman

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    1. automotive PCV valves are continuously open when the engine is running EXCEPT when extreme overpressure occurs from an intake backfire

    True but only if connected to manifold vaccum to keep it open.


    2. With no intake vacuum modulation on a KLR PCV valve mod, wouldn't a passive, one-way PCV valve in the crankcase vent hose simply open

    Yes in the case of installing it on the KLR it would take crankcase pressure to open it. This means that it would open when the piston creates the pressure on the downward stroke

    3. If positive crankcase pressure forces the piston up, wouldn't the piston have to OVERCOME that positive pressure on the downstroke.

    The force is only slight and could only be measured by gauges that operate below one trillionth (10<SUP>&#8722;12</SUP>) of atmospheric pressure (100 nPa), and can reach around 100 particles/cm<SUP>3</SUP>
    <SUP></SUP>
    <SUP></SUP>
    <SUP></SUP>
    <SUP>Like I said I could not tell you if it would work on the KLR</SUP>
  16. DrMoto

    DrMoto Adventurer

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    Location:
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    2000 klr250 bought last year w/2k miles; now 6k.
    Thought about replacing clutch cable, thought about lubing it, didn't do either.
    Pulled the lever coming to stop light this morning, got nuthin'. Except a tow, a few hours later.

    Surprised no one within 100 miles has the cable I need? (Both Kawi dealers in town now gone)
    Lesson learned: just do it, and buy a spare.
  17. MrBob

    MrBob Certified Geezer

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    You must be psychic :lol3
    When touring back in the day we'd tape a spare clutch cable to the existing one. Just switch the ends and you're back on the road.
  18. truck6driver

    truck6driver The Fireman

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    I have never thought of that. Great idea.

    Ray
  19. truck6driver

    truck6driver The Fireman

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    Well I have kicked to one too many times. Going back to the doctor for knee pain after a hard kick yesterday. :cry

    I cannot loose a career by kick starting a bike so.....
    I will be putting the bike up for sale in the next couple days.


    Just a heads up for you guys.
    http://advrider.com/forums/showthread.php?t=788148

    Ray
  20. newcastleadam

    newcastleadam Artful Tagger

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    I posted this back in September when I first got it, now about to dig into it a bit. It has an odd noise (don't they all), which I think is a cam chain slap. This is after new cams installed.

    <iframe width="560" height="315" src="http://www.youtube.com/embed/wSCkfAHFqAQ" frameborder="0" allowfullscreen></iframe>

    I'll be opening it back up and checking for wear, any thoughts now?

    Thanks,