Engine Trouble flying horse 80cc engine wont catch gear

Discussion in '2-Stroke Engines' started by calebbullock, Sep 7, 2013.

  1. calebbullock

    calebbullock New Member


    I have a flying horse 66/80cc engine kit i installed 2 months ago. I was riding last week when the engine just started revving i decided to try to keep it alive for awhile just revving it and it could. I decided I was close enough to home to pedal. My problem is (while the engine is not running) i can release the clutch lever to put it in gear and can still roll the bike. The clutch does not lock the back tire like it should.

    any help would be nice,
    Much Appreciated

  2. Purple Haze

    Purple Haze Active Member

    The clutch setup on these things are extremely simple. On the shaft, there's a spring (looks like a car engine valvespring) with a slotted nut that adjusts tension. Sounds like it has backed off and lost all tension. The good news is it is simple to remove if you have the gear puller tool. Remove the clutch cover, then loosen the star nut. If it is loose already you have found your problem, if not proceed to pressure plate removal. Then remove the cover on the drive side and pull drive gear. The whole clutch shaft will then come out, no need to remove clutch gear. The drive gear has a woodruff key in it, don't lose it. After you get the shaft out, you'll see how everything works. Put enough tension on the spring that it gets a firm feel, but not so tight that it binds. Hopefully, just the star nut has loosened, but it usually doesn't since it has a screw that locks it into place. If the screw has loosened, you'll see it easily enough. Another way to tighten the nut on the spring is to remove the cable housing from the case, then stick a screwdriver into the hole and bind the nut, then move the bike backward to tighten. This will only work if the nut hasn't come off the threads completely, but it's worth a try as it will save you a lot of disassembly and reassembly.
  3. calebbullock

    calebbullock New Member

    thanks for the help and its not the flower nut on the clutch cover plate its gotta be something in the drive shaft or inside like you were talking about. i was also looking on the other side where the engine sprocket is because if the clutch lever is released and you roll the bike it will still move freely
  4. Purple Haze

    Purple Haze Active Member

    It could be the woodruff key that holds the drive gear in place on the shaft. They are designed to shear off before damage to the gear occurs. There's also a woodruff key on the clutch gear.
  5. HeadSmess

    HeadSmess Well-Known Member

    theres four in total. magneto, obviously not it.

    main pinion.
    clutch gear.
    output sprocket.

    more than likely the main pinion key as its the hardest to install.

    found more than one not inserted at all.

    theres two thickness keys, 2.5 and 3mm. i believe the crank uses the 2.5, the clutch shaft takes the 3's...