Only getting 22MPH (35KPH)

Discussion in '2-Stroke Engines' started by CPC, Apr 12, 2009.

  1. CPC

    CPC Member

    ****, I have a question, Im only getting 22MPH full bore. I have a Chinese 66 cc engine with a 44 tooth rear sprocket. I want to get at least 35MPH with a cruising speed of 25MPH. Ive installed a NGK spark plug gaped to around .o2o greased the primary gears with blue marine grease, drilled a 1/4" hole in stock exhaust opposite of the primary outlet. Im running regular gas @ 20:1 put on a better air cleaner, but still have the 50cc stack carb. Any ideas how to increase my speed, I plan on getting a 36 tooth sprocket if this poor girl can come up on the cash and a good carb from spookytooth also. Thanks!
     

  2. bamabikeguy

    bamabikeguy Active Member

    Breaking them in, with throttle variations, during the first 1-200 miles is vital to increased performance.

    Did you do those steps, 10-20-15-30 seconds at various up/down throttle speeds?
     
  3. CPC

    CPC Member

    never heard of such a thing! Not even researching here!
     
  4. CPC

    CPC Member

    Ugh! I dont know what else to try....played with the carb to no improvement tightened the clutch up in case it was slipping, wasent. what else could it be?
     
  5. DetonatorTuning

    DetonatorTuning Active Member

    altitude, your high enough to be loosing 10+% easily, with out remedy.

    sorry,
    steve
     
  6. Mountainman

    Mountainman Active Member

    break in -- hard to explain at times

    sounds like you may be ((past the break in period)) ???

    it's always a good THING to do
    although a little hard to explain at times
    there has been much said regarding break in around here though

    I kind of run from 1/3 to 2/3 throttle -- slowly up and down
    when engine is new
    turning it off every so often so as to cool off

    ps -- running a little rich while breaking in -- always a good THING

    just another ps -- don't climb any mountains while new -- unless I ((pedal hard)) to assist

    ride that MB THING
     
    Last edited: Apr 12, 2009
  7. CPC

    CPC Member

    Ive got like 150 miles on engine. according to my calculations, Im only running @ 5000 rpm wide open.

    I'm starting not to believe all these ppl here that say there getting 30, 40 50+ MPH, the math just does NOT add up! even with a 36 tooth sprocket you'll only get 31.4 MPH @ 6000 rpm.... I do not think these lil engines run that fast under load, just my opinion, recently formed.
     
    Last edited: Apr 12, 2009
  8. cooltoy

    cooltoy Member

    With gears you could gain speed and still be able to climb hills.
    You would not believe what a difference shifting gears can make.
     

    Attached Files:

  9. CPC

    CPC Member

    ah i wanna, but I wont pay $200 for that kit from sickbikeparts
     
  10. lordoflightaz

    lordoflightaz Member

    Write it off as a business expense. You won't regret it Maybe get the 11 tooth sprocket as well.

    Also, you could check for air leaks, intake exhaust and top end.

    BTW right at 150 mile my top speed sort of jumped up while breaking in the engine. I hit 35 in 6th at less than WOT on a 49cc. Before that never really got over 28.
     
  11. CPC

    CPC Member

    found an air leak on the new spark plug.....shoddy chinese paint job, so I scraped and sanded around and presto, got all my compression agine. As for the shifter kit, Im not too sure about their setup for the price....****, I could buy 2 spare engines for that price! I'm thinking of doing whit a 27 tooth sprocket, I should get 35 Mph @ 5000 RPM then, but I am unsure of the stress on my engine, I do have some hills to go up to get to the other part of town ( about 1/2 mile @ prolly 10% grade). Wish there was a was to shift between a 36 and a 27 tooth sprocket, any ideas how that could be done?
     
  12. CPC

    CPC Member

    I do like the Idea of such a span of gears the shifter kit allows and the 11 tooth drive sprocket....If I did get that kit & the 11 tooth with the equivalent of a 27 tooth rear sprocket I would get 38.5 Mph @ 5000 RPM.....Ummmm wounder if I could somehow add and electric start if I got that kit....
     
  13. This is my opinion and I'm sticking to it.

    1) You live in Grand Junction. That's even higher in altitude then in Denver where I'm at well Northglenn actually. That's a handicap right there. Bring it down to sea level and you would be thinking you're on a different bike.
    2) The fastest I have ever gone on my HT China 2 stroke whatever you want to call it also a 66cc is 23 mph and that's with a 44 tooth sprocket fully broken in running beautiful redline bla bla bla.
    3) IT'S A BICYCLE MAN with ONE GEAR! Want more speeds and better pulling invest in some GEARS.
    4) (this one people will differ on me with) These engines have TERRIBLE sellers from China that say WOW 35 MPH 200 MPG 80cc!!! Running these engines at WIDE OPEN THROTTLE ALL DAY LONG and SOMETHING will give out. Would you run your car in 1st gear at 50 mph in the highway all day long?
    FORGET what people say about macho speeds man sorry for offending but if you want long life then cruise at under 20 mph your engine will love you really it will.
    5) Do you want speed? Then get a drum brake up front and get that shift kit. Oh that's like #3 sorry. Whatever single speed you go with there's no real compromise if you want to go faster than 20 mph SAFELY. If you resign to go slower then a 44 tooth rear sprocket is the PERFECT compromise in pulling power and wind in your face just not enough to require goggles.
     
    Last edited by a moderator: Apr 12, 2009
  14. fetor56

    fetor56 Guest

    150 Miles is not broken-in.....give it 250 & possibly even more to reach maximum consistency.Switch to a fully synthetic oil thereafter.
     
  15. CPC

    CPC Member

    This is the break in proceedure I followed:

    Do this:
    From Moto814

    1) Assemble the engine properly and torque all fasteners to specs.

    2) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.

    3) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

    4) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.

    5) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

    6) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), take the bike off the stand and put it in gear. Take it for a ride. During this ride you want to keep the engine under a load at all times. Do not coast. Do not let the bike idle. Do not allow the engine to stay at one RPM. Riding on a mild slope is fine for this, as is slightly dragging the rear brake the entire time. Do this for about 15-20 minutes. Then shut the bike off.

    7) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

    8 ) Re-torque the head and base nuts.

    9) Go ride.

    The cool-down steps are crucial to this operation. You must let the engine cool completely for the break in process to work properly.

    Also, do the warm up procedure I outline here before EVERY ride. Your top ends will last much longer if you do.
     
  16. Mountainman

    Mountainman Active Member

    wowwwwwwwwwwww that's almost as intense as rocket science !!!

    riding that THING with varing speeds with serveral cool off periods works fine
    no WOT for a while and when we do finally -- just little shots

    this seems easier to remember
    plus -- doesn't take all of the fun out of -- riding that MB THING sideways !!!
     
  17. CPC

    CPC Member

    much easier, faster than doing it the normal" way.....3, 4, 5 tanks of gas.... Oh no, I DO NOT think it takes one of these engines that long to break in......**** buy a new car and you only have a 500 mile break in keeping under 55 Mph.....what everyone is telling ppl is OVERKILL! these are junk engines, tolerances are not that close. Question: Do you "break in your weedwacker"? No, you dont, same engine (well almost!)
     
  18. Mountainman

    Mountainman Active Member

    CPC
    noticed that you got the CHIC Couriers THING going on there

    do you have any Mountainmen working there ???

    if not -- the (((((UNION FOR THE MOUNTAINMEN))))) may be a calling !!!

    ride that MB THING sideways
     
  19. CPC

    CPC Member

    No mountainman, wanna move out here for a job? Make your own $$$ 50% commision rate is what I pay my couriers! Id hire you if you wanna move, maybe I could sell you a franchise......interested?
     
  20. Mountainman

    Mountainman Active Member

    as long as I don't

    as long as I don't have to shave my legs
    not a good look on a mountainman

    true -- I did try it once
    with shaved legs my MB top speed went from 22.5 to 22.7 mph
    but going down this old dirt road one day
    someone threw cow pies at me
    as they screamed -- what pretty legs you have there MountainBOY !!!

    ride that THING at 22.5
     
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