Discussion in 'Whizzer Motorized Bicycles' started by cesspool72, May 8, 2011.

  1. cesspool72

    cesspool72 New Member

    have a 99 whizzer.cast iron cylinder,heres the problem.if i ride it for a long period of time it looses compression and will not start til it cools back off later.has around 100 miles on it since reaplacing cylinder.is this an easy fix?also the pedal brake has been kicking back while bike is in motion was wonering what this might be also.pedal brake is unusable cause kicks back in opposite direction very hard.thanks for any suggetions.

  2. Al.Fisherman

    Al.Fisherman Active Member

    Lost compression...sounds like a bad head to cylinder seal. I don't know about what you have but, all internal combustion engines all basically run on the same principal. I'd mill both cylinder and head over sandpaper, install NEW gasket and use proper torque. As par as the peddle..no idea without looking at the set up.
  3. KilroyCD

    KilroyCD Active Member

    Cesspool, what you're describing with your engine sounds like what normally happens with the original WC-1 cylinders because of the valve seats. However, you said that you have a cast iron cylinder on it now. I think Quenton has a lot of information about the cast iron cylinders, so he would be the one likely to have an answer.
    As to your brake, the same thing happened to me - twice! The first one did that right before the hub catastrophically failed with the spoke flanges on the left side breaking free. I'm lucky I was going very slow and didn't wreck. I got a replacement wheel from Whizzer. The second time it happened I replaced it with a Shimano CBE-110 coaster brake. No issues there.
  4. RdKryton

    RdKryton Active Member

    It sounds like the valves are adjusted too tight. When the engine gets up to operating temp, the valves will not close completely. This is the decrease in compression you see and explains why it starts only after it cools. The coaster brake is in need of rebuilding or at least needs to be completely dissembled, cleaned and lubricated.

    Last edited: May 9, 2011