Page 4 of 9 FirstFirst ... 23456 ... LastLast
Results 31 to 40 of 88

Thread: KTM 2T troubleshooting

  1. #31
    Join Date
    May 2008
    Location
    Northford, CT
    Posts
    1,571

    Default

    Call mike. He lives right up route 8.
    -Gabe, is a racist.

    Matt 9/19/10

  2. #32
    Join Date
    Aug 2008
    Location
    beacon falls
    Posts
    6,211

    Default

    On today's episode: New Top End, No Joy!

    TLDR: New top end didn't do shit. we think its the reeds. anyone have a valve or photo of one i can use to compare mine to?

    Kurtz came over and helped me work through a new top end. As soon as we popped the jug off it was apparent that this was not the problem. Cylinder walls were spotless, piston was in great shape. We swapped it anyway.

    Buttoned it all up and tested compression got about 30 more PSI but still not near the ~170 that is recommended. Popped the plug in, no joy.

    Pulled the plug after trying to start, dry as a bone, barely the scent of fuel on it.

    Took carb apart AGAIN. Kurtz confirmed all jets look clear, nothing obvious there.

    the only remaining piece is the reed valve, so we took it off. I read somewhere that a good test for them is to fill them with water. should take ~15 seconds for water to leak out. I couldn't even get mine to fill up under the faucet it was leaking so fast. It looks like the cage/case itself is cracked. there are HUGE gaps in the molded plastic. And at the right angle, there are gaps in the reeds. they aren't frayed or broken. they just appear to not be sealing.

    So, it is my understanding that the reed valves are supposed to seal during the compression stroke, and open during the intake/vacuum stroke to suck in air and fuel. If these cracks are allowing compression to leak out, it is essentially pushing air back into the carb rather than sucking fuel and air into the cylinder. I was in fact getting a weird "cough" every few strokes of the kick starter, and it seems like that is actually the air going back in to the carb.

    Operating theory is that the spark did quit on me. The resulting turbulence in the cylinder from being underway with no spark/ timed explosion created surges in compression in the cylinder and caused the reed cage to fail.

    If you made it this far, does anyone happen to have a reed valve/cage for this bike laying around that i can either drop in and use to test, or get a photo of so i can compare to my potentially broken one?

  3. #33
    Join Date
    May 2009
    Location
    Pomfret
    Posts
    10,291

    Default

    Reed petals are cheap. Just buy a set and put them in.

    Wait. Is it stock or v force cage?

    If it's v force and it failed just get a new rad valve. I like boyesen because they are metal.
    Last edited by csmutty; 08-12-2018 at 04:06 PM.
    -Christian LRRS/CCS #856 ECK RacingGMD Computrack Boston | Pine Motorparts/PBE Specialists | Woodcraft | Street & Competition | OnTrack Media

    2011 Pit Bike Race CHAMPION!

  4. #34
    Join Date
    May 2007
    Location
    Meriden
    Posts
    4,550

    Default

    Like smutty said.. Get the reeds. They are fairly reasonable and could be an easy fix. Mine were shot and had to get new one's. Also my bike had the rad valve so I had to order special reeds
    LRRS# 772 NETRA#3772
    Boston Tier 1 Racing
    Amsoil/DP Brakes / AXO America/Vortex Racing/ Woodcraft/Armour Bodies/Racer Gloves/Hiflofiltro oil filters

  5. #35
    Join Date
    Aug 2008
    Location
    beacon falls
    Posts
    6,211

    Default

    Fairly certain these are stock vforce reads. There are no screwed/bolted clamps to replace the petals, they are press fit in. And the failure seems to primarily be the plastic cage.

    I want to see a photo of, or be able to test a stock set up before I drop money on a replacement aftermarket

  6. #36
    Join Date
    May 2007
    Location
    Meriden
    Posts
    4,550

    Default

    They are press fit? Wow did not know they had that. I hear you on wanting to see the set up before you buy. I bought stock reeds only to find out I had the rad valve
    LRRS# 772 NETRA#3772
    Boston Tier 1 Racing
    Amsoil/DP Brakes / AXO America/Vortex Racing/ Woodcraft/Armour Bodies/Racer Gloves/Hiflofiltro oil filters

  7. #37
    Join Date
    May 2009
    Location
    Pomfret
    Posts
    10,291

    Default

    I still don't understand plastic parts in the intake. Never liked v force for that reason.
    -Christian LRRS/CCS #856 ECK RacingGMD Computrack Boston | Pine Motorparts/PBE Specialists | Woodcraft | Street & Competition | OnTrack Media

    2011 Pit Bike Race CHAMPION!

  8. #38
    Join Date
    Oct 2006
    Location
    Naugatuck, CT
    Posts
    25,291

    Default

    The reed petals seem fine. The cage itself has gaps in it, which look almost intentional...or like the plastic cage just catastrophically failed in four places.



    That seam, circled in red, is wide open.


    Sent from my iPhone using Tapatalk

  9. #39
    Join Date
    Aug 2009
    Location
    Maine
    Posts
    1,228

    Default

    If you look on eBay, you can see other examples that look the same. Those appear to be intentional.
    771 Racing -=- FaceBook
    Backed by Heroic Racing Apparel
    A-ko - 1992 FZR400RR SP / Mistake - 1992 WR250ZD / Facade - 2003 YZF-R6 / 2000 LS650P

  10. #40
    Join Date
    Aug 2008
    Location
    beacon falls
    Posts
    6,211

    Default

    then idk wtf is left to do.

    If i get home in time tonight i'm going to try Josh's idea (shared over text) and put some premix right down the plug hole, thread in the plug and kick. hopefully it tries to start and we can at least confirm that it WANTS to run but isn't getting fuel.

Similar Threads

  1. Replies: 13
    Last Post: 10-10-2011, 06:26 PM
  2. Triumph guys - Detailed technical troubleshooting question
    By DucatiMichael in forum The Garage
    Replies: 30
    Last Post: 08-10-2011, 07:51 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •