4G centrifugal clutch

Discussion in '4-Stroke Engines' started by Barry, Jul 6, 2012.

  1. Barry

    Barry Member

    Hello,
    Just finished installing an HS 4 stroke 4G trans and while she lit off on the second pull, the clutch will not disengage at idle. Any leads to a web site the show how to make ajustments?
    Tanks
    Barry
     

    Attached Files:


  2. The_Aleman

    The_Aleman Active Member

    Which Huasheng and 4G do you have? Is it the keyed shaft setup or the short tapered shaft?
     
  3. Barry

    Barry Member

    Grubbie 4G clutch

    Hello Aleman!
    After some more trouble-shooting, I find that the clutch bell assembly was locked tight on the brass bushing. I tried a number of things to free it up, to no avail. I did find something on the University of You Tube that said that this bushig must be oil soaked for 24 hours. I'm on the road all this week, bushing is soaking on my workbench, and will hopefully do the trick. If not, I plan on taking the bushing over to a machine shop to have a couple of thousands milled off.
    Thanks!!
    Barry
     
  4. The_Aleman

    The_Aleman Active Member

    Milling the bushing won't help much, all it will do is make your clutch bell noisier. The best thing you can do is get a real Oilite bushing.

    McMaster-Carr Part# 6659K33, I recommend getting a few of them - they're cheap!
     
  5. Barry

    Barry Member

    My HS 4G has a 1/2" straight crankshaft

    Good Morning Aleman,
    I'm back from a week in Atlanta, I had ordered a few of the McMaster bushings before I left and found while checking the shipping status that the store was only 12 miles from where I was working!
    At any rate, the bushing/clutch housing problem is totaly fixed.
    New problem: I'm running a Sick-Bike shift kit to an internal 3 speed rear hub. On my first run around the block I found that the gear ratios were PERFECT and I was smiling largely. Second trip around the block the clutch would no longer totally engage (did some big time smoking). I'm hearing that this clutch is worthless and a better replacement one is available. Do you know what it is/who sells it?
    Tanks
    Barry
     
    Last edited: Jul 16, 2012
  6. The_Aleman

    The_Aleman Active Member

    Heh, definitely shouldn't be smoking like that. You sure you didn't over-oil the clutch assembly? Only a couple drops on the bushing flange is needed from time to time.

    These clutches are actually quite durable, my first one lasted well over a year, and I only replaced it because the center hole got a little reamed out. The shoes still had plenty of life.

    I procured my replacement clutch from www.bicycle-engines.com, turned out to have better springs than the one that came with my 2010 model 4G. Looks like they're in stock, too.
     
  7. Barry

    Barry Member

    Looks like they are out-of-stock.
    Thanks
    Barry
     
  8. Barry

    Barry Member

    Hey Aleman,
    I think I've been barking up the wrong tree on this clutch issue. I now beleive that the one-way bearing on the rear pulley is the real culprit. What do you think the ramifications would be if I just drew a weld on it?
    Thanks
    Barry
     
  9. The_Aleman

    The_Aleman Active Member

    I've never dealt with the one-way bearing, as my 4G is a solid pulley model. I've heard of people disassembling the one-way and filling it with JB Weld or welding it tho.

    Upside: you will now have engine braking

    Downside: you lose freewheeling, which makes the bike a little harder to pedal with engine off
     
  10. Barry

    Barry Member

    I'm now a happy guy, 3 miles down the road with bugs in my teeth! The Grubbie 4G that I bought must have been manufacuctued on a Friday afternoon but, is now running sweet.
    On the clutch problem: Mine came out of the box with the clutch bearing pretty much welded to the bell. I brought the bell and bushing to a machine shop and had them put a bit of a bevel on the bell and turned the bushing down so it would turn freely. I found that when you install it, torque the retaining bolt down, the bell was actually becoming one with the bushing/crankshaft. (crappy design). The fix is to add small washers to the point where when you tighten the retaining bolt down, the bell still is freewheeling. (see pic).
    The one-way bearing failure at the one mile mark was fixed by the JB Weld suggested by the gal at bicycle-motors.
    At any rate, I'm now a happy camper and am tweeking and fine-tuning the build.
    Barry
     

    Attached Files:

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