two stroke engines

Discussion in 'Motorized Bicycle General Discussion' started by flyboy605, Jul 16, 2008.

  1. flyboy605

    flyboy605 New Member

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    HI TO ALL
    I just installed the "Popular" two stroke engine and I think it was a waste of time and money, they vibrate so bad that you can only run about 1/2 or less throttle and the motor is very very noisy.
    I also have a Whizzer and it is a real joy especially after I installed the ''QUENTION" FIX, hope this helps answer some questions--- Flyboy605:ride2:
     
  2. thatsdax

    thatsdax Member

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    What kind of bike are you using it on? Also..There are at least 50 different versions of the 2 stroke. The smaller the version the smoother. Some are smooth as silk. Others vibrate more. Depends.. Typically they all get much smoother after 300-400 miles. Did you mount your engine on a chopper bike? Also... Lose mounting or improper mounting accounts for over 50 percent of any excessive vibrations. I personally own and ride at least 4. I have built over 300. I have never ever had one with vibration that was objectionable. I have had a few that were smooth as silk and as smooth as any Titan 4 stroke. Most vibrate at the higher revs but never did it become objectionable to the point where I did not have a smile on my face !!! Give us the low down.. Maybe we can help. Thanks..And.. Enjoy the ride...
     
  3. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    Kind of a general statement. My 2-stroke is pretty smooth at WFO, 40 mph, and maybe a tad noisy up close, but I have an expansion chamber.

    Whizzers look OK, but are expensive, not that modifiable, and frankly have too much junk hanging off them. Not my cup of tea.

    What question were you trying to answer?
     
  4. jasonh

    jasonh New Member

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    I have an earlier Dax kit (according to the guy I bought it from) and it's as smooth as an ice cold beer on a hot day.

    Could also try making some real automotive type mounts to limit vibrations.
     
  5. flyboy605

    flyboy605 New Member

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    HI to all
    I will try and shed a little light on my bike First I am not a "Newbie" I am long of tooth and have been playing with this type of stuff for a long time so the obvious stuff (Loose mounts ect ect) does not apply. I am using a "Moon Dog" 26in bike I got at W_M and had to devise a Motor Mount but it is very solid, bolted solid to the frame no rubber mounts, when I am running about 1/2 throttle its very noisy a vibrates a lot, when I pull the clutch lever in and let up on the throttle its gets quiet and of course no vibration, this about sums it up it idles well and starts easy, All ideas will be appreciated Thanks FB 605
     
  6. captainrichhill

    captainrichhill New Member

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    Mine vibrates alot! I have pieces of innertube under each mount. I'm hoping it will smooth out as it gets broken in. It has already gotten faster. I only have about 35 miles on it so far.
     
  7. jasonh

    jasonh New Member

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    Well unfortunately with these motors coming from up to 50 different factories, plus the poor QC, it's gonna happen.
     
  8. FileStyle

    FileStyle New Member

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    ride it like you stole it!
     
  9. MotorbikeMike

    MotorbikeMike Dealer

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    Hi just a note here as it greives me to have so many pieces of un-substaintiated "facts", on chatboards.

    At last known count of easily identifiable factories assembling the 2-stroke in-frame chines kit, there was 1 main carb company, and 7 factories assembling and selling engine kits.

    Years ago, prior to any of us ever seeing these kits, and when they were still legal in China, there may well HAVE been 50 factories, but certainly not now.

    Now adressing vibration patterns on the 2-stroke. The "China-Fires" as we used to call them are VERY crudely balanced! Some not at all, some engines run pretty nice, and some shake like a wet dog. ANYONE who doesn't believe this either lacks experiance with these engines, or is not speaking truth! Some are faster than others, some smoother, some last a long time and some seem to have the "Rice Krispie" syndrome whic is they "POP" right out of the box!

    As to Pablo's ideas about Whizzer? Iniatailly this Just do the 1950's thing which is "Ride one and you'll buy one".

    Scondly, since when is a dramatically de-tuned 4-stroke unmodifiable? That would meah I could not have hopped up my old 327 chevy to the point she will do 105mph in third gear, with an M20 Muncie hooked to a 3.5 gearset in a 9-inch Ford?

    Carb, compression, cam, tuning, pipe, porting......all this is possible and more.

    Mike
     
    #9 MotorbikeMike, Jul 17, 2008
    Last edited: Jul 17, 2008
  10. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    I like those big block Briggs you see on racing karts.
     
  11. chopper

    chopper New Member

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    All these fixes unfortunatley are just band aids. What we really need is a good way to balance the engine. Thats the source of all the vibs.
     
  12. captainrichhill

    captainrichhill New Member

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    Has anyone been successful in balancing one of these HT engines? My buddy just got a Kings kit( I think) and right out of the box it's smoother then my engine and I have about 400 miles on mine.
     
  13. Creative Engineering

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    Yes...Very successfull...But you can not balance a bent crank! I have had 4 bent cranks recently that were pulled from new engines.

    Jim
     
  14. captainrichhill

    captainrichhill New Member

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    Interesting! I new concidered a bent crank. That could be it. Quality control is the chinese biggest problem.
    Thanks
    RH
     
  15. NunyaBidness

    NunyaBidness Active Member

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    My buddy got a 2 smoke and we installed it on his new wally world moondoggie. It rode great out of the box. I got my motor shortly there after and had a lot of the problems I saw some folks having. My bro had none on his first motor. As I got everything straightened out on my motor and got it running very good, he got a second motor. His second didn't run as good as his first and neither of his now ran as good as mine. I outweigh him by about 70lbs and really have no problem keeping up with him and his bike is lighter than mine as well.

    Making a long story shorter, I really like my motor and he hates both of his. Since his good motor is no longer running as good as it once did and he has been unable to fix it, after trying almost everything possible.
     
  16. gberry50

    gberry50 New Member

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    I seem to be having vibes at the point where it should be comming on the power band
    other wise fairly smooth. I bent the exhaust pipe flange a couple of weeks ago
    and had an exhaust leak blew oil all over front of engine but the vibes went away and
    bike run like a stripped ass ape , I was able to experiance the full power band.and engine sounded good.I dont think balance is the problem .Is anyone producing a decent
    expansion chamber for the gas bike 80cc?
     
  17. Cabinfever1977

    Cabinfever1977 New Member

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    its all in what motor mounts you use,if you dont use rubber then theres probally going to be more vibrations.
     

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