Slipping Clutch on a Grubee Huangsheng

Discussion in 'Frame Mounted Engines' started by Irish John, Jun 26, 2008.

  1. Irish John

    Irish John Guest

    I think my centrifugal clutch is slipping. It wasn't noticeable before with the 48T sprocket but with the 56T it revs up from a standing start faster than it actually accellerates. It's not too bad yet because the engine revs die back on hills when the bike is struggling whereas if the clutch was slipping badly the motor would rev on hills without going forwards.
    Is there a simple way I could fix this or might it be related to swapping over to a wet GB from a greased one and a bit of slip is caused from the oil in the clutch chamber. Should I worry about it? I'm changing back to a 48T tonight because my instincts tell me the little motor doesn't like peak revs.
    Anyway I'd like to know if I can fix whatever is worn in the clutch. I've never looked inside the centrifugal clutch since I built the bike.

  2. HoughMade

    HoughMade Guest

    I'm sure it is slipping from a standing start. Mine is too- but at cruising speed, mine does not slip. That's the nature of running "wet" and is the reason you can start from a standing stop with out it chattering. I always try to get the bike moving with some pedaling or at least pushing off. When I do that, there is little slippage down low and, as always, none at greater speeds.
  3. Irish John

    Irish John Guest

    Your right HoughMade, it's back to normal now that I've chaged back to 48T sprocket. I changed the 50\50 gunk in GB and silicon sealed the cover but it leaks. Thought I was liberal with the gasket silicone sealant but I mustn't have used enough. Too late to reseal it now so I'll have to put up with the leak dripping on my lovely silencer and caramelising to a golden brown that I need a steel wool pad to get off. The moral of this tale is not to be tight fisted with the expensive sealant cos its penny-wise and pound-foolish. Tonight I blasted over the mountain on a pitch black night and descended into beautiful cold fog only to rise up out of it into warm sea air on the hilltops like getting into a warm bath. Black southern sky full of stars. The trusty Indian Paific (my bike) was really going good when a car came up from behind and a quick burst of siren - it was the police - they just wanted to congratulate me for being lit up like a Christmas tree plus I had luminous jacket and trousers on and then they admired my bike. There's nothing so good as a Grubee 4-stroke on a lonely country road on a winter's night but I could have done without the police siren.
  4. HoughMade

    HoughMade Guest

    When I put my box back together, I used a bead of silicone on the inside of the gearbox mounted to the engine. I then put the original gasket into that bead, then I put another bead on the gearbox cover where it seats against the gasket so the gasket is now seated on both sides by silicone. By the way, before I did any of this, I cleaned the gearbox inside and out with laquer thinner and then carb cleaner so there was no oil on the mounting surfaces. After I mounted the cover and tightened it down, I put a small bead around the seam on the outside of the box just for fun. I did not refill the box until the silicone had over 24 hours to fully cure. So far- no leaks.

    This is one reason I tapped a 6mm hole into the gearbox and installed a drain plug- I don't want to have to take the cover off again unless I have to repair something that is broken. This way, I can drain and experiement with different lubricants to my heart's content without taking the cover off.

    Sounds like a great ride- kind of a annoying to be pulled over, but it's a positive thing to know how they are thinking about you and your conveyance.
  5. nsideus

    nsideus Guest

    Irish, I was having slippage with the 50/50 mix at around 3,000 to 4,000 rpm on acceleration I switched to lithium grease and have had no problems since. I am running a 56th.
  6. Irish John

    Irish John Guest

    Thanks Nsideus, I hope I get this 50/50 gunk to work. Since I changed back to the 44T the clutch hasn't been slipping but I think I could make it slip if I accellerated hard from a standing start. The grease was Ok but I read all the good things about the 50/50 and decided to try it. Time will tell. I wonder how you guys get 30mph from a 56T. I could only get 26 mph flat out. I also got too much vibration in my saddle - felt nice but worried me too much. My engine definitely likes the 44T better. I think there is a difference between the Honda/Grubee guys and the Huangsheng\Grubee guys. The Hondas go about 5mph faster it seems to me. I think they rev about 500 prm more and I'll bet there valves are seated better. There's something there that explains the difference.
  7. dougsr.874

    dougsr.874 Active Member

    Don't use oil or any combo. of in the gearbox..............fill it full of wheelbearing grease......been running same gearbox for 5 yrs using this method