Pedal-less acceleration?

Discussion in 'Motorized Cruiser Bicycles' started by motorizedinDC, Sep 8, 2016.

  1. mikadonovan

    mikadonovan New Member

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    I completed my first build a couple of months ago (49cc on a Kulana Hiku cruiser). This also is a heavy bike. I can now take off without pedaling, just by grabbing a handful of throttle and dumping the clutch. I made this possible by adding an expansion chamber (huge difference in low end torque), boost bottle and leaned out my jetting. I have found the machine is running better the more I ride it, and running a 25 to 1 mix vs the 18 to 1 break in mix has also improved performance. I have about a 100 miles on the engine at this point.
     
  2. Tyler6357

    Tyler6357 Member

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    Sweet, I knew an expansion pipe would help!

    brnot
     
  3. LandSpeedRecord

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    The more miles you put on it the stronger it will get also as the rings wear in etc. I would guess the average CG gains 30 percent or more power in the first 300 to 500 milds as the compresion comes up and it breaks in. You can lean out the oil mix also to 32 to 1 on conventional oil. I run them at 32 to 1 right out of the box and most of my customers stay at that mix and some switch to 50 to 1 synthetic is they want to eliminate smoke and possible 2 stroke smell on their clothes commuting to work.
     
  4. Tyler6357

    Tyler6357 Member

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    What do you think of Opti2 at 100x1? I've been using this stuff for the life of my 69cc PK80 China Girl engine. I did my break in at about 90x1 and 100x1 thereafter. It seems great so far with low smoke and carbon build up. I'm at about 1900 miles.

    http://www.ebay.com/itm/Opti-One-Ga...098079?hash=item4638e2cb9f:g:uKUAAOSw5cNYHL7j
     
    #24 Tyler6357, Jan 4, 2017
    Last edited: Jan 4, 2017
  5. sbest

    sbest New Member

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    The chrome is thin on these engines, not as durable as nikasil.
    50:1 seemed to result in scratches. I've had better luck with 32:1.

    Tyler, have you looked at your cylinder lately?

    Steve
     
  6. Tyler6357

    Tyler6357 Member

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    Not since I replaced the head with a Fredhead about 500 miles ago.
     
  7. LandSpeedRecord

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    The oil mix is such a huge discussion and many have had good results with many mixes and oils. I think lot of new people are mis led by the factory double recommendation for break in is my main point, I think if you want to be super safe run 24 to 1 for a tank but many of these motors wont even start on 16 to 1 so I never use or recommend that much on a new motor. As for opti at 100 to 1 this thread is the first I have heard a problem with it so I may wonder if some pieces of debris didn't cause the scratches or something else. I suspect it is a good street mix but I do not have first hand experience.
     
  8. LandSpeedRecord

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    sbest are you running opti at that ratio?
     
  9. Tyler6357

    Tyler6357 Member

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    Thank you for giving your option. As a dealer I thought you might know more than me about it.

    brnot
     

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