i think my "80cc" has issues. top speed only 28mph with shifter kit...

Discussion in 'Motorized Bicycle General Discussion' started by jerseykat1, Oct 12, 2008.

  1. jerseykat1

    jerseykat1 New Member

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    let me start off by saying the shifter kit from SBP is great makes my ride so much smoother.

    My problem is that i have a top speed of only 28mph and thats only achieved going down hill in my 7th gear. i can cruise at 23-25mph but when i try and go faster it just does not want to go any faster, and the motor just doesnt have the power to go any faster.

    So far i have sealed the intake manifold to carb with silicon, sealed the intake manifold to engine with silicon, i have a new champion spark plug, a new ignition wire (after i replaced this i was faced with the disappointment of only 28mph because my ignition no longer kills my speedo), and i moved the c/e clip to the top most position on the needle (did not make a noticable diffrence) after my first movement to the lowest postion on the needle made it run like crap (it runs the same from what i can tell being on the second notch from the top as it does on the very top notch). Have i done something wrong or is this typical of a mostly stock "80cc" motor? Ohh i am running 20:1 gas mix premium 93 octane fuel. not sure how many miles i have on the motor but it is atleast 20 miles.

    i believe i should atleast be able to hit 30-35mph with the shifter kit, but my motor is just lacking the balls right now.

    Please advise.
     
  2. stude13

    stude13 New Member

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    keep up the brreak in. the speed will come.
     
  3. jerseykat1

    jerseykat1 New Member

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    how many miles is needed for break in?
     
  4. Andyinchville1

    Andyinchville1 Manufacturer/Dealer

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    HI,

    Not 100% sure on the effects of High octane VS low octane gasoline but I have read that these low compression engines do better on LOW octane fuels rather than premium....Try that on the next tank and maybe you'd be surprised?

    Hope this helps you.

    Andrew
     
  5. misteright1_99

    misteright1_99 New Member

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    My engine was 3 tanks, and the power started to come on.....
     
  6. jerseykat1

    jerseykat1 New Member

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    i am on my second tank, actually i would say my first full tank. i never filled it up completely because the damn gas cap would leak, finally got that fixed. would you say about 100 miles is sufficient to break it in? Thank you andy i will switch back to regular tomorrow. i can just use what i have left for my weed wacker, and leaf blower.

    i am finally able to keep track of my mileage so i guess i will start to worry after 100 or so more miles.

    thank you.
     
  7. Easy Rider

    Easy Rider Santa Cruz Scooter Works

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    Under 30 mph doesn't sound right especially coming from a new motor with one of Palbo's kits on it. My HT motor right out of the box hit low 30's w/o the shifter kit. What are the symtoms at top speed?
    Does it vibrate alot at high rpms?
    Does it sound like its starving or getting too much fuel?
    Is there anything besides the kill switch hooked up to the white wire?
    Can you feel if anything is binding when you ride it around without the motor running or just spinning the wheel?
    Another thing to check is your main jet. Remove the bowl and unscrew the main jet and use a needle to clean it.
     
  8. jerseykat1

    jerseykat1 New Member

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    it vibrates a bit excessively when it hits top speed.
    it does feel like its fuel starved.
    nothing hooked up to the white wire.
    no binding when i pedal manually.
    i guess i will have to pull the carb apart and see what the problem is.
     
  9. Easy Rider

    Easy Rider Santa Cruz Scooter Works

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    I remember when I got my kit, I had to clean my carb out because it had this vasoline looking lube in the carb bowl. A couple of months ago, I had a problem with the carb on my Morini. It was starving for fuel so I removed the bowl and the main jet was clogged. I did my needle trick (poke the main jet) and its been running fine ever since.
     
  10. jerseykat1

    jerseykat1 New Member

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    should i enlarge the hole a bit? there was a little bit of dirt in the bowl, the jet did not appear to be clogged, but i am positive the dirt floating around in there was not helping. i do have a fuel filter installed now but i would say i did about 3-5 miles without a fuel filter, before i found this forum.

    i am gonna see if i can find that thread of normans with the overhaul procedure.
     
  11. misteright1_99

    misteright1_99 New Member

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  12. NunyaBidness

    NunyaBidness Active Member

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    did that fix seal the gas cap air tight also, if so you might be having a fuel flow problem.
     
  13. jerseykat1

    jerseykat1 New Member

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    its not air tight, if i shake it up enough it will leak some fuel.
     
  14. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    I would get a good plug reading and take it from there. If you don't know what's going on inside the combustion chamber, you are just whistling in the dark when it comes to changing things to "make it run better".

    28 mph is not a terrible speed for the first few hundred miles.
    Some engines break in after a hundred, some seem to take 400...some never do run very fast or quit vibrating, luck of the draw there.

    I would go to 24:1 synthetic oil and then read the plug.

    20:1 is too rich in oil, making an artificially lean mixture.
     
  15. jerseykat1

    jerseykat1 New Member

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    it wont even rev very high in neutral. its almost like there is a rev limiter on the engine, the vibration isnt too bad at all. when i last pulled the plug out it was black and moist (earlier today) i since switched to regular (seemed to make it slower) and added a little less oil to the mix (the blue stuff) so i should be around 24:1 if not closer to 30:1 using 87 octane. i am now after screwing around with the carb last night and some tinkering this morning only getting 25 mph, and the engine wont rev very high at all, when i first got the kit it would rev really high. i am going to take it out to get my lunch in a minute then take a look at the plug when i get back.
     
  16. Ghost0

    Ghost0 New Member

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    You say you sealed your intake and exhaust manifolds but did you match them. You should have noticed that the intake and exhaust manifolds are round and the ports are not. This causes them to be partially blocked. That is the first thing I would try. I would then check to see if your exhaust pipe if flowing freely. Make sure there is nothing blocking or hindering he exhaust. Then I would start playing with fuel mixture but like was mentioned check your plug. It is the only way to tell how your mixture is without an exhaust gas analyzer.
     
  17. jerseykat1

    jerseykat1 New Member

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    [​IMG]
    [​IMG]
    ok this is after 1.5 miles of driving today and numerous tests in my driveway. it looks pretty normal in my opinion. what do you guys think. but like i said in the last post it will not rev very high which is whats limiting my top speed, from the sound its making i would guess its only reving to about 3500-4krpms then it just hits a wall and surges a bit. with or without load on the engine.
     
    #17 jerseykat1, Oct 13, 2008
    Last edited: Oct 13, 2008
  18. jerseykat1

    jerseykat1 New Member

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    i am sure that you are right about that giving me more power but i don't think that is my problem right now (i did pull the muffler off and it is not blocked) it did at one point during the time i owned it rev very freely without load, now it wont.
     
  19. jerseykat1

    jerseykat1 New Member

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    question: which c/e clip position on the needle in the carb makes it leaner and which makes it richer?

    also i have an ignition coil (from ford vehicle coil on plug set up) single coil on plug style coil that only requires 2 input leads to fire. Do you think it would work if i put the 2 leads from the china motor to this coil? i would try it but i am afraid it will mess something up.
     
  20. Ghost0

    Ghost0 New Member

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    Go to a higher clip position to lean it out, lower clip position to richen the mixture. I wouldn't try the coil swap. Keep it stock. I would change plug and plug wire though. You may have fouled your plug and it just isn't working well now.
     

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