Adding a centrifugal clutch to 2 stroke PowerKing

Discussion in 'Frame Mounted Engines' started by arkives1, Oct 25, 2009.

  1. arkives1

    arkives1 Member

    I have two bikes, one of which has standard clutch, the other has centrifugal clutch added. There is a signifigant difference in power and speed with the centrifugal....it's slower. Anyone else experienced this? I don't know if that is to be expected but would think power should stay the same. Thanks!
     

  2. biken stins

    biken stins Member

    Yes. Somewhat. The take off with the centrifugal seem a bit slower. Not much noticed at top speed.
     
  3. arkives1

    arkives1 Member

    Centrifugal clutch power loss

    Thanks Biken......I expected take off to be slower and you're right it is, I have lost signifigant power and speed at the top end. I suspect the clutch is not expanding all the way to drive at full speed.Possibly defective bearings or internal springs. I contacted Powerking and they promptly shipped a new clutch to me under warranty. It hasn't arrived yet, expected tomorrow. I'll post results when I get it installed and see if it makes a difference. PowerKing has been great to deal with, prompt shipment, fair pricing, and courteous service and quick with that too. I'd recommend Zoombicycles to anyone, I just ordered a new centrifugal and pullstarter for the second bike. Wider crank is from bicycle-engines.com. they too have been prompt and courteous and the quality is good. The pull start and centrifugal is great for anyone in the city with respiratory distress, much easier on the lungs and heart.
     
  4. Skyliner70cc

    Skyliner70cc Active Member

    I don't notice any difference with mine. There is more rotational mass so acceleration and top speed may suffer but it shouldn't be signifcant.

    As for acceleration. I have a SBP parts shifter kit with smaller output sprocket on right side of engine and large 34tooth mega gear derailleur. This thing has great acceleration to redline and will climb anything out there.
     
  5. arkives1

    arkives1 Member

    centrifugal clutch power loss

    Thanks a bunch Skyliner. You have pretty much confirmed my suspicion of a defective part. My next project is to do the same thing you did with using the jack shaft set up and using the deraileur for gearing. I have just acquired an OCC chopper and am putting a 66/80 cc engine on it. It's a standard one speed bike but maybe I can change the rear hub for gearing. Unfortunately any motorized bike capable of more than 30 mph becomes classified as a motorcycle in Wisconsin thus requiring registration and motorcycle license.
     
  6. Skyliner70cc

    Skyliner70cc Active Member

    Consider taking it easy on a new clutch for a bit. It took a while for my clutch to get bedded in properly. I wouldn't use no pedal starts until it does. I glazed the pads on my first centrifugal clutch but easily fixed by sanding the glaze off with some emory clotch.
     
  7. arkives1

    arkives1 Member

    Centrifugal clutch discussion

    I have been taking it easy so far Skyliner and it does seem to be getting a bit better on the top end speed. Unfortunately today I managed to pick up a piece of steel pallet strapping lying in the wet leaves and it tangled with the chain tensioner and into the spokes. Pulled one spoke thru the rim and bent a few others. Now the rim is badly warped and I need to find a new wheel that will work with the gearing I have in this one. The damaged one is a lightweight alloy and I should have replaced that wheel before motorizing it. The strapping would have still popped spokes but perhaps not bent the rim. As I came pushing the thing home on the front wheel only, the girlfriend said "Are we having fun yet?" WOMEN!
     
  8. iron_monkey

    iron_monkey Guest

    Lack of pick up/slipping could also be oil contaminating the inner surface of the clutch bell where the pads touch.
     
  9. arkives1

    arkives1 Member

    Centrifugal clutch problem on Powerking engine

    Thanks Iron monkey. Powerking sent me a new clutch, it works beautifully. I can see no oil or grease with in the casing and I have taken it apart. I did find a distorted spring though and put the old flywhell in the parts bin well labled as defective but maybe useful for parts at some point. The newest problem is with another engine of unknown brand. Things look alike but in trying to add a centrifugal clutch to that one I am unable to remove the small gear, stripped the threads on the clutch removal tool trying. I'm wondering if I can remove the dry clutch plates etc and perhaps pry the thing off that way. I don't care if the gear breaks but wouldnt want to damage the shaft or related parts. I may have to take the whole engine apart to get at it. It's interesting that the powerking engines I have all start very easily and run quite smoothly with a little warm up. This one is balky,hard to start and simply refuses to idle at any speed remotely close to an idol. I'm going to post this problem in the forum and hope someone else has already found a solution. A great bunch of guys in here!
     
  10. iron_monkey

    iron_monkey Guest

    Your best hope was the cog removal thingo. Did you try heating the thing before trying to remove it?
     
  11. arkives1

    arkives1 Member

    adding centrifugal clutch and small gear removal

    I haven't tried heating it yet, the only torch I have is a propane unit. Besides there has been gas in the tank and fuel lines and carb, I'm a bit careful about getting flames near that stuff. I've drained all that I can but still......May try Fat's idea of grabbing it with vice grips and cracking the gear. Got the engine off the bike so I can take it to the shop to work on it now. I'd drill small holes around it to ease cracking but I'd bet that it's a bit too hard to drill.
     
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