skyhawk in frame tank racer build

Discussion in 'Photos & Bicycle Builds' started by mikemarley, May 14, 2015.

  1. mikemarley

    mikemarley Member

    ive got them already, just had to get a case. my problem is i dont use stock bearings, or unbalanced crankahafts, or un ported cylinders or heads. i use a welded balanced crank with racing grade bearings, and its been ported for a reed valve. my problem is id be breaking down the new motor just for the fact i dont use the stock bearings, i go waaaay to fast id lock them up very quickly. i just used half a case and matched it with my original
     

  2. butre

    butre Well-Known Member

    11 tooth sprockets shouldn't be used without modification. I've used up to 12 tooth with the help of a die grinder
     
  3. Frankfort MB's

    Frankfort MB's Well-Known Member

    Why not use the stock sprocket. Seems easier to change the rear sprocket
     
  4. butre

    butre Well-Known Member

    they only make down to 32 tooth for the manic mechanic rear. using an 11 tooth is roughly equivalent to a 4 tooth drop in the rear. plus a larger drive sprocket decreases chain wear.

    at 9000 rpm with a 32 tooth rear on a 26 inch wheel the difference between a 10 tooth and an 11 tooth drive sprocket can be 5 miles per hour assuming the motor has the power to handle that gearing. using a 12 tooth can be a 10 mph difference, again assuming your motor has the power for it
     
    Last edited: Jun 7, 2016
  5. Frankfort MB's

    Frankfort MB's Well-Known Member

    I'm guessing you can get major speed out of the different sprocket sizes if you have enough motor for it
     
  6. mikemarley

    mikemarley Member

    Yeah but low end becomes less reliable. My reed engine didnt have trouble cruising just gotta burn the clutch a lil at launch. Im running a 30 tooth sprocket atm
     
  7. mikemarley

    mikemarley Member

    finally got the best exhaust i could get for making these bikes scream. kx pro circuit system with a silencer too. this thing should get alot more power from the chamber setup with my porting nd reed setup. gotta 30 tooth rear end but thinkn bout dropping to a 28. disc rear ends only though gotta stop quick when youre movin that fast lol
     

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  8. Randall

    Randall Member

    Hey Mike, where did your friend get his 12 volt gen at? I got mine from gasbike and it doesn't work. Thanks.
     
  9. mikemarley

    mikemarley Member

    got mine from gasbike. still works too just gotta add a head gasket to some bikes to lower the compression enough for it to spark still with it on
     
  10. Arty

    Arty Active Member

    Mike:
    I'm curious about your comment about lowering compression to make the 12v gen. work. I tried putting a gen from wonderful creations on my rig - but it simply won't start with it on.
     
  11. mikemarley

    mikemarley Member

    yeah i had that same problem. the magneto doesnt have enough voltage to burn gas at that compression but i took out the plug and it was still firing with the gen on just not as well. i lowered the compression by putting an additional head gasket on it to lower it minutely. lowers your performance a little but definitely fun still
     
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