Centrifugal Combination Pull Start & Centrifugal clutch

Discussion in 'Transmission / Drivetrain' started by birdmannn101, Aug 2, 2012.

  1. birdmannn101

    birdmannn101 Member

    Has anyone bought and used one of these kits and can say whether they are good or bad?
     

  2. Fabian

    Fabian Well-Known Member

    They are both excellent accessories, but you will need to do a simple modification to the centrifugal clutch to give long life.
    I'll send you a PM, pictorially detailing the method and explaining the logic why it needs to be done.
     
  3. Skyliner70cc

    Skyliner70cc Active Member

    Pull start is a waste of money; it'll break. Centrifugal clutch on my many builds is more reliable than the engine and has never failed me yet without any mods.
     
  4. Fabian

    Fabian Well-Known Member

    Pull start has been quite reliable for me - depends on which pull start you get. Biggest problem is the bolts making contact with the pulley causing all sorts of issues, but this issue is easily solved.

    By design, the centrifugal clutch will fail (especially if used in a single speed application); there is simply no way it can have long life unless modified, upon which it gives excellent reliability.
     
  5. Scootmeister

    Scootmeister Member

    I installed a so called "Heavy Duty" pull start from BGF on my 66cc HT. It worked great the first 20 pulls until the cord frayed then broke. Who sells a reliable one? Could you PM me with the centrifugal mods? Thanks.
     
  6. Fabian

    Fabian Well-Known Member

    If you de-burr the guide where the rope runs through the housing and impregnate the starter cord with Teflon grease, you won't have any problems with cord breakage.

    PM for centrifugal clutch mods coming your way.
     
  7. Skyliner70cc

    Skyliner70cc Active Member

    Upgraded starter cord is steel braided wire which failed on its 4th pull..embarassing since it occured on a group ride with other MB riders.

    Now have 211 hours on original centrifugal clutch with no mods of anykind and lots of abuse which included 11 miles at a 6% grade with several sections exceeding 8% grade.


     
  8. Fabian

    Fabian Well-Known Member

    By design it "will" fail if not modified, unless you have leaky crankshaft seals.
    That your centrifugal clutch has gone 211 hours is proof miracles do happen. Time to make preparations with the Catholic church to get your centrifugal clutch ready for canonization.
     
  9. Skyliner70cc

    Skyliner70cc Active Member

    No leaky seals, bushing on it appears to be fine with no appreciable wear but then again, I do not idle engine excessively and disconnect manual clutch if I do allow engine to idle.

    No miracle, several of my other rides that I've built for others 3-4 years ago are still on the road with no centrifugal clutch issues. What's the big secret and why the PM for your special mod to the clutch to make it more reliable?
     
  10. Fabian

    Fabian Well-Known Member

    Ahhh, there's your problem Skyliner:


    With a centrifugal clutch, my preferred method of operation is to be lazy and leave the manual clutch to be a piece of forgotten hardware.
    Filthy steep hill climbs and beating mercilessly on your CC with stop-starts every 20 or 30 yards will have it begging for some lubrication, but it seems you have a secret modification of your own for the CC.

    Now i never said i had any secrets, because the people i share secrets with don't know how to keep a secret :grin5:
     
  11. wjohnson

    wjohnson Banned

    I looked around until i found a kit with out a clutch. The clutches are another thing to malfuction..lol i have had bad luck with clutches..
     
  12. Fabian

    Fabian Well-Known Member

    I've had good luck with clutches, in fact i wouldn't go anywhere without my centrifugal and manual clutch and pull-start combo.
     
  13. birdmannn101

    birdmannn101 Member

    Fabian, Which clutch and pull start did you finally end up with, JN MOTORS or GAS BIKE?
     
  14. Scootmeister

    Scootmeister Member

    Fabian, thanks for the tips on the pull start cord problem. I came up with another solution that has worked fine so far. First, I moved the hole for the pull cord several degrees to make for a direct pull from my seat when starting the engine. This substantially reduced the friction between the cord and the guide. Second, I replaced the soft plastic guide that came with the pull start housing with a hard pastic guide from an old Homelite blower engine that a friend was going to throw out. Third, I replaced the inferior cord with one from an old Briggs engine (American made I suspect) that is 20 years old and has never frayed with regular use. There is just no substitue for quality and that will always be the case.
     
  15. Fabian

    Fabian Well-Known Member

    There is most definitely no substitute for quality, particularly when a motor bicyclist re-engineers quality into the component that was taken out by the manufacturing process.
     
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