Sprockets 66cc Skyhawk Screw Loose. It holds the drive gear to the drive shaft.

Discussion in 'Transmission / Drivetrain' started by RebelMiniMe, Feb 25, 2014.

  1. RebelMiniMe

    RebelMiniMe New Member

    Anyone point me in the right direction? Previous owner said he damaged threads. Should I rethread it into the drive shaft? Anything else I should check/replace?

    Said it has 400 miles on the engine. Very oily looking. What should I look for or replace on the engine before I take it out for a spin?


    Newbie Skyhawk owner from Ohio. There is snow on the ground so no time soon I guess.

  2. butterbean

    butterbean Well-Known Member

    Not sure what you paid for the bike, but a new engine can be had on ebay for probably less than $100. Might not be a bad idea.
  3. RebelMiniMe

    RebelMiniMe New Member

    It was tough enough getting the wife to let me get the bike for free. One screw is bad and I should get a new engine? Sure I can't just fix it? Would rather fix it if possible.
  4. butterbean

    butterbean Well-Known Member

    If it's only the threads on the screw itself that are damaged and not the threads that the screw goes into that are damaged, you can replace the screw and the engine is fine. If the threads where the screw goes in are damaged (which is likely, as I can't think of a scenario in which both would not become damaged at the same time), then there is nothing you can do. The engine is shot if that gear can not hold itself in place. But there is good news. You can buy the replacement screw (I'm not sure where, I haven't looked for two stroke parts in well over a year as I drive a four stroke now), and put it in, if it stays in you're golden. If it doesn't, you need a new engine. As far as the whole wife situation, all I can say is good luck. I already had a bike when my wife and I met. She didn't like it that much either at first, but I explained it like this. No one is perfectly safe from idiot drivers, but the more I ride, the more experience I will get, and the more aware of my surroundings I will become. I pay as much attention on the road as I can, and so far I've been paying enough attention to avoid every idiot who has threatened my safety. The possibility is there that one day I won't be so lucky, but until then I have to get back and forth somehow (I don't have a license) so let me make use of this cheap form of alternative transportation and enjoy it while I can. I wear a helmet and that's the best thing I can do to protect myself. She accepted that explanation and that settled that discussion. Honestly if your wife is that uncomfortable with it, you may want to think about giving up now, because she won't be happy until she makes you give it up, and then you'll resent her for it. I speak from experience, not specifically with motorized bikes and relationships, but with other things.
  5. RebelMiniMe

    RebelMiniMe New Member

    So the 'screw' goes into the drive gear shaft? Is that part, the 'drive gear shaft?', not replaceable ?
  6. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    I really doubt if you need a new engine.

    Please post a pic of the flat head screw so I can see the threads.

    Do the threads inside the crank end look damaged?

    Post some pics of your bike too.
  7. butterbean

    butterbean Well-Known Member

    I mean, you might be able to re-tap the crank end, but it's doubtful, but you can try. Alternatively, you can replace the crankshaft, but how much work are you willing to go through for a $90 engine? Ask your wife how much time she is willing to let you spend fixing it? Because a new engine will go in much faster than a new crankshaft, and probably even faster than trying to re-tap a hardened shaft, which probably won't work anyway.
  8. Purple Haze

    Purple Haze Active Member

    I've had that same thing happen in the past, so my advice is to first check if the key is still in place. If it is, see if the threads are ok on the screw. The threads inside the crank are most likely ok. If the threads on the screw look ok, use Loctite blue on it and reassemble. You won't have to worry about it again. Remember, Loctite is your best friend on these quivering little suckers!
  9. RebelMiniMe

    RebelMiniMe New Member

    Will snap some closeups of the screw and crankshaft this evening. I am willing to invest in loctite, I bet a tube of loctite could fabricate the whole screw. Can I take it down to the car shop and ask him to tap weld the gear onto the crankshaft?
  10. butterbean

    butterbean Well-Known Member

    Loctite will not fabricate an entire screw, it's an adhesive, not something you can mold things out of. You can have the gear tack welded probably, but if you do, you're never going to be able to replace the crankshaft, so when this one goes you'll be needing a new engine for sure.
  11. RebelMiniMe

    RebelMiniMe New Member

    Didn't have time after coaching at the Y. Will try again tonight for a shot of screw and crank shaft.

    Come on, loctite fabrication was a joke!