1. 2 Stroke Husqvarna Motorcycles Made In Italy - About 1989 to 2014
     WR = 2st Enduro & CR = 2st Cross

All 2st Carb replacement between Mikuni TMX and Keihin PWK

Discussion in '2 Stroke' started by MattR, Feb 23, 2010.

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  1. MattR 2T Forum Clerk

    Location:
    Temperance, MI
    Husqvarna Motorcycle:
    WB165, SM610
    Other Motorcycles:
    Yamaha FZ1
    Just following up on a thread that I started...

    My 38mm PWK air striker (from Kelly @ Motosportz) arrived yesterday. :applause:

    Here are some installation notes for others that are planning to make this swap. The PWK is about 15mm longer from inlet to outlet. This makes the PWK a very snug fit between the boots. I could not install this carb by simply pulling back the airbox boot (like I've done with the Mikuni TMX). The extra length made it a bit too much effort to swing the PWK into place.

    So Plan B went into effect...
    I unbolted the lower subframe and both silencer bolts. Then, I swung the subframe up. While this is a minor hassle, it allows you to attach the PWK to the reed valve manifold easily. Swing the subframe back down and attach the airbox boot to the carb's inlet. Done! :cheers: Other notes: the inlet/outlet diameters did fit the boots without issues. The airbox boot is slightly closer to the rear shock spring. It rubbed previously with the TMX and now it appears to contact a bit more. Not a major issue, but a concern that I will keep an eye on for potential wear.

    After mounting, all of the jetting changes will typically be only main jet and needle/clip changes. This can all be done by swinging the carb while mounted in the boots. FYI... the PWK is slightly shorter than the TMX, so the bottom of the float bowl has more clearance above the engine case. This helps when swapping out the main jet.

    As-received:
    Main = 185, Pilot = 45, Needle = Blue @ #4 clip, air screw = 1.75 turns out, Slide = 7. You also get the Red needle and 2 main jets (175 and 180). The jetting as received may be too rich but I will try it first since it is "more safe" than being too lean.

    First impressions:
    Bike was initially hard to start. Then I realized the idle screw was set too far out. After resetting the idle screw, the bike started and idle perfectly. A quick ride around the neighborhood and the bottom-mid range felt great!!! It is a vast improvement over the Mikuni TMX. I can not wait until I get my first ride on the trails. Thanks to Kelly and JD Jetting for making these pre-jetted PWK's available for our bikes. :thumbsup:
    MattR, Apr 3, 2010
    #41

  2. Norman Foley Husqvarna
    Pro Class

    Location:
    Trumansburg, NY... The Beautiful, Finger Lakes
    Husqvarna Motorcycle:
    82 250WR 86 250WR 93 WXE350 03 TE610
    Other Motorcycles:
    '85 Fantic 300 '12 HUSABERG TE250
    I put mine on today. Plan B was Plan A for me..... From Walt's post I knew it would be a tight squeeze, so I also tipped the subframe up to simplify the installation. The '09 is a little easier, with only one silencer mounting bolt. Mine started right away, but I needed to adjust the freeplay in the stock cable. The cable was plenty long enough, as I have it routed behind the top clamp. I also had to tighten the idle screw, once I had the cable correct.

    I changed the jetting before I installed it, using Kelly's set up (178M, 45P, Blue needle 3rd from top, AS 1.5-2). We run different pipes and silencer, but thought it would be a good starting point. His set up was for temps of 35-65F, which would be usual for me at this time of year. Of course it was 85F plus today. Bike starts and idles well and much less spooge than TMX. It did well in the bottom and top, but midrange could be better. No bog, but not quite as crisp. It's supposed to be 20 degrees cooler tomorrow, so we'll see. I'm tempted to drop the clip to 2nd position. What temps do you switch to red needle?
    Norman Foley, Apr 3, 2010
    #42

  3. Johnnymannen Husqvarna
    AA Class

    Location:
    Sweden
    Anyone got a good jettingtip for my PWK when it arrives? I live at sealevel and we have about 50F here now Any recommendations for Street/Motard use and woods use? Any changes for the different types of riding?

    Johnny:sweden:
    Johnnymannen, Apr 4, 2010
    #43

  4. Motosportz CH Sponsor

    Location:
    Vancouver WA
    Husqvarna Motorcycle:
    2021 TE250i, 570 Berg, 500 KTM, 790R
    Other Motorcycles:
    many
    172M, 45P, Blue needle 3rd from top, AS 1.5-2
    Motosportz, Apr 4, 2010
    #44

  5. Motosportz CH Sponsor

    Location:
    Vancouver WA
    Husqvarna Motorcycle:
    2021 TE250i, 570 Berg, 500 KTM, 790R
    Other Motorcycles:
    many
    MAttR / Norm, I have no issues installing and removing the carb without doing the subframe. Once I had done it once or twice it is EZ.

    Norm,
    I bet you need to go a little leaner. Try moving the clip one.
    Motosportz, Apr 4, 2010
    #45

  6. Norman Foley Husqvarna
    Pro Class

    Location:
    Trumansburg, NY... The Beautiful, Finger Lakes
    Husqvarna Motorcycle:
    82 250WR 86 250WR 93 WXE350 03 TE610
    Other Motorcycles:
    '85 Fantic 300 '12 HUSABERG TE250
    Will do!
    Thanks!:cheers:
    Norman Foley, Apr 4, 2010
    #46

  7. wallybean Mini-Sponsor

    Location:
    Montana
    Kelly,

    I agree it isn't real difficult once you have done it. I use two hands on the carb. Left hand on the bowl and right hand on the top coming in from the other side with your arm over the seat to stabilize the bike. You can get enough leverage this way to bend the filter side boot in enough to swing the carb into the engine side boot.

    Walt
    wallybean, Apr 4, 2010
    #47

  8. Motosportz CH Sponsor

    Location:
    Vancouver WA
    Husqvarna Motorcycle:
    2021 TE250i, 570 Berg, 500 KTM, 790R
    Other Motorcycles:
    many
    exactly how i do it.
    Motosportz, Apr 4, 2010
    #48

  9. Johnnymannen Husqvarna
    AA Class

    Location:
    Sweden
    Thanks, kelly! I´ll start from that!

    Johnny
    Johnnymannen, Apr 5, 2010
    #49
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