centrifugal clutches

Discussion in 'Whizzer Motorized Bicycles' started by MaxGlide, Jul 2, 2011.

  1. MaxGlide

    MaxGlide Member

    Hello all.... anyone know where I can get a centrifugal clutch for my J engine Whizzer?

    Also I've read there are 50mm, 70mm and 90mm versions so which one would be the best for my area, which is very hilly (Vancouver, Canada) and my weight which is 190lbs.

    Thanks..... Wayne

  2. MaxGlide

    MaxGlide Member

    Edit, Belt adjustments or centrifugal clutch?

    Before I go in the direction of a centrifugal clutch maybe proper belt adjustment might do the trick on my J engine.

    I have a Whizzer service manual plus I have read everything I can in here on adjusting the belts and tried to follow instructions and it still feels not quite right.

    Whenever I put the bike under load it feels like the belts are jumping... not slipping... There is sort of a "ka-chunk, ka-chunk, ka-chunk" feeling/noise and the bike has this sorta thump, thump, thump feeling to it. It feels like when the pulleys are pulling, a bit of slack accumulates in the belt then that slack "jumps" around the pulley.....? Does that make any sense?

    There is no slippage, the engine is not revving while the bike moves slowly.... once I am cruising and moderately changing speeds it is quite smooth.

    I adjusted the front belt so that there is 5/16 clearance between pulley and housing (manual advises 3/8" so I'm 1/16th off) I adjusted the rear belt so that it is about the same tension as the front (going too tight apparently loosens the front belt) I did tighten the back once too much and the skipping was worse. Problem is I can't go any looser on the rear belt/chain as the chain is too loose as it is and being a one inch pitch it is at the point where it is quite loose but now quite loose enough to remove a set of links.

    Sooooo........ would a centrifugal clutch help with this or is tension between front and back belts just as crucial with this type of clutch?

    Any advice/tips would be very much appreciated.

    Thanks in advance..... Wayne
  3. tone2crazy

    tone2crazy Member

    sounds like one of your pulleys might not be true.
  4. MaxGlide

    MaxGlide Member

    Well the pulleys should be true... Lee, the Whizzer Wizard from EZ Motorbike did a rebuild on it and the main flywheel should be good.

    I got a new bearing from Memory lane so that should be good.

    I wonder if maybe the actual pulley has a problem? I will check that. As well, I wonder if maybe one of the pulley surfaces might be such that, under load, the belts slip and grab due to some un-eveness (?) due to some kind of buildup. I suppose the belts might be worn but they have maybe 200 miles on it.

    Thing is when I am cruising it runs smoothly, it only "k-chunks" when I load it.

    It is quite hilly around here.

    Back to my original question then.... would a centrifugal clutch help with the tension/slippage part?

    Thanks.... Wayne
  5. MaxGlide

    MaxGlide Member

    Anyone know if Lee Guenther is around? I sent him a PM a while back and find it odd he has not either posted on the forum or answered me.... he's usually pretty quick.
    I hope everything is alright.

  6. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Wayne,

    Sorry been busy 24 hours a day with EZ Motorbike, just trying to fill orders.

    I sent you a message earlier explaining why you can't use the late model automatic clutch on your vintage "J" motor [too wide].

    Sounds like the rear belt sheeve isn't centered correctly. If the rear sheeve is off center or bent it will tighten and loosen the belt as the wheel rotates. The rear sheeve alignment is most noticable at lower speeds and will smooth out at higher speeds. You might want to try a different brand of front belt as the vary greatly between different companies.

    Have fun,
  7. MaxGlide

    MaxGlide Member

    Hi Lee,

    Glad all is well.... I was a wee little bit worried there not hearing from you!

    I will check the sheave again.

    AS I mentioned at low speeds, most noticeable when under load, there is that chunka chunka chunk that is totally gone at cruising speed.

    I will also recheck belts for wear, glazing and the pulleys too.

    I did not receive your pm re the clutches but it sounds like I gotta make what I have work.

    Thanks for your help once again!

  8. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Make sure the clutch spring has a fair amount of tension, as it will help smooth out the belt tension.

    Keep us posted.

    Have fun,
  9. MaxGlide

    MaxGlide Member

    I thought I should check that. I'm looking for a set of shims, or whatever you call them, that will show how much space there is between the coils and I'll compare that to what the manual says it should be at.

    In the meantime I found a proper Elgin rack and chain guard, had them painted and am in the process of mounting them. Also found a Columbia springer fork and that is also being painted and will get that on as well.

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