Break In Bike runnning VERY rough

Discussion in '2-Stroke Engines' started by agrmodz, Jul 5, 2016.

  1. agrmodz

    agrmodz Member

    the bike is an 80cc powerking mototrised bike off ebay, its still running in, its using 16:1 gas to oil mix, it was running fine for a while but then it started making a very loud noise when running, when the clutch is in its very quiet and it doesnt make the noise when the clutch is out and im giving it gas it makes this strange noise...
    I'm not sure what it could be, please help guys!!!
     

  2. agrmodz

    agrmodz Member

    I had the bike on an angle so the carb was up on an angle aswell, im going to adjust it all later..
     
  3. crassius

    crassius Well-Known Member

    open covers and look for rub marks - something may need tightening/adjusting
     
  4. agrmodz

    agrmodz Member

    Okay, i'll take a look soon, its like something is sitting on the back wheel and its whizzing but its coming from the motor, the motor is brand new...
     
  5. crassius

    crassius Well-Known Member

    search here about grease for bucking bar, clutch cam, and bevel gears too
     
  6. Frankenstein

    Frankenstein Active Member

    Check for head gasket leaks, just yesterday I looked over a bike, running very rough didn't idle right and made the baddest almost smacking sound, especially under load, leaking from the rear of the head gasket, put a new annealed copper one in, torqued to 15 foot pounds, 5 pounds at a time, cross pattern, and walla, sound gone, idled nicely, and towed his 300 pound ass like nobody's business.
     
  7. Frankenstein

    Frankenstein Active Member

    Oh and be prepared for the worst. Had an engine with main bearings that failed 3 times, each time before they failed, rough riding, and the oddest whizzing/whirring sound. Then sounded like a bunch of rocks being blended, then stopped.
     
  8. agrmodz

    agrmodz Member

    Luckily mine fixed, the motor was on too much of a lean and the motor wasn't tight enough on the frame, now the motor does 60km with stock parts which is just over 37.2 mph. Extremely happy with these motors, ive ordered 2 and they both go amazing speeds for stock parts!
     
  9. Frankenstein

    Frankenstein Active Member

    Congratulations!
     
    agrmodz likes this.
  10. gary55

    gary55 Active Member

    Another place to look is the cover of the gear on the motor that drives the chain. Sometimes material needs to be removed so the chain has clearance. Pop out the three screws and pop it off. You will probably see where the chain is hitting the cover on the flat portion closest to the mag. cover. I think this prob. arose back when they changed form 410 to 415 chains, but the engine dimensions didn't change to allow for the larger links. Just guessing. I do this to every engine I build.
     
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