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

All 2st Bike quit

Discussion in '2 Stroke' started by dirt-dude, Jun 7, 2010.

  1. dirt-dude Husqvarna
    AA Class

    Location:
    Pa.
    Sunday my son came out of a corner and about halfway
    down the straight the bike bogged and back fired and
    quit. We thought it had fouled a plug but that wasn't
    the case. We found the crank seal on the stator side
    had been pushed out of the case, also found the reeds
    had broken, they appear to have been pushed out not
    drawn into the engine. Cylinder, piston and crank all
    appear ok. The bike is an 04 CR-125 was running great
    up till this happened. I think the fuel ignited in the
    crank case any ideas what could have caused this?
    dirt-dude, Jun 7, 2010
    #1

  2. gem Husqvarna
    A Class

    Location:
    British Columbia
    Check for a sheared flywheel key, which allowed the flywheel to slip altering the timing.
    gem, Jun 7, 2010
    #2

  3. dirt-dude Husqvarna
    AA Class

    Location:
    Pa.
    The flywheel key was ok and the stator mounting plate was tight.
    dirt-dude, Jun 7, 2010
    #3

  4. Dirtdame Administrator

    Location:
    Rock Springs Wy
    Husqvarna Motorcycle:
    11 WR300,13 WR125,18 FE501
    Other Motorcycles:
    17 Beta Xtrainer
    Does the sparkplug still fire if you turn the engine over? Maybe something went wrong with other ignition parts (CDI or coil). CDI going out will make a bike do some strange things as it takes a dooky. My older Honda started to bog and misfire when the ignitor went bad, right before it quit running all together.
    Dirtdame, Jun 7, 2010
    #4

  5. dirt-dude Husqvarna
    AA Class

    Location:
    Pa.
    Yes it has spark. There"s allot of oil on the piston and crank, I'm
    going to pull the clutch side apart and check the crank seal on
    that side. What I'm thinking is possibly the seal on the clutch
    side failed and drew enough oil into the crank case to cause the
    crank case pressure to spike before the piston reached the transfer
    ports.
    dirt-dude, Jun 7, 2010
    #5

  6. MOTORHEAD Husqvarna
    Pro Class

    Location:
    Mount Vernon, Indiana
    Husqvarna Motorcycle:
    none
    Other Motorcycles:
    2014 YAMAHA YZ250
    That's a very good possibility if the crank case vent is plugged.
    MOTORHEAD, Jun 7, 2010
    #6

  7. dirt-dude Husqvarna
    AA Class

    Location:
    Pa.
    Well I think that theory's shot. The trans vent was clear. I hooked
    a mighty vac up to the trans vent and used a bore scope to look
    into the crank case while I had the trans pressurized found no oil
    coming in, and the trans held pressure so the seal on the clutch
    side is not likely the cause of the failure. I think I may just replace
    reeds and put the seal back in on the stator side and see what happens.
    I had checked the trans fluid level was still right at the inspection hole.
    dirt-dude, Jun 8, 2010
    #7

  8. MOTORHEAD Husqvarna
    Pro Class

    Location:
    Mount Vernon, Indiana
    Husqvarna Motorcycle:
    none
    Other Motorcycles:
    2014 YAMAHA YZ250
    Well please share whatever you find. This is a goody.
    MOTORHEAD, Jun 8, 2010
    #8

  9. MOTORHEAD Husqvarna
    Pro Class

    Location:
    Mount Vernon, Indiana
    Husqvarna Motorcycle:
    none
    Other Motorcycles:
    2014 YAMAHA YZ250
    OK, never mind. I was thinking too hard on this. You just blew a reed, it loaded up, back fired and blew the seal out.

    Replace the seal and reeds and go.
    MOTORHEAD, Jun 8, 2010
    #9

  10. dirt-dude Husqvarna
    AA Class

    Location:
    Pa.
    Replaced the crank seal and reeds, started on the second kick. Everything seems ok so far. We ran it up and down the field several
    times carberated properly and pulled fine. Hopefully it was a fluke
    occurrence and we won't see it again.
    dirt-dude, Jun 20, 2010
    #10

  11. dirt-dude Husqvarna
    AA Class

    Location:
    Pa.
    Thanks motorhead I didn't see your latest post till I just reposted.
    I was thinking the same thing when I couldn't find the smoking gun.
    dirt-dude, Jun 20, 2010
    #11