Grubee skyhawk 2 gearbox question

Discussion in '4-Stroke Engines' started by cheap ride, Apr 3, 2008.

  1. cheap ride

    cheap ride Guest

    Hi all, I have a Huasheng 4 stroke kit on my bike with a grubee skyhawk 2 gearbox, i am trying to find out if it is possible to buy a wet clutch to go into the gearbox, then i can half fill the gearbox with some good gear oil, like 80w 150 or similar, this should increase the life expectancy of the gearbox and make it run really quiet i hope, has anyone got knowledge of where i can buy such a clutch ? i would appreciate any leads:grin:
     

  2. HoughMade

    HoughMade Guest

    The instructions say it can be run as-is, wet or dry and many people here have run theirs with gearlube. Not me, but I am considering it.
     
  3. nsideus

    nsideus Guest

    The grubee works best wet so it is the wet clutch your looking for. If you run it dry it will stick. I drill a small hole in the case cover near the clutch and tap it for a screw. Give the clutch a couple of sqirts of gear oil (not so much it drips) and spin it to make sure it has and even coating and spins freely. I then assemble the gear box using a bead of silicone gasket maker this keeps the gear box from leaking. When the silicone has set up give a few squirts of gear oil through the hole perferably while the engine is running. Take it for a test ride if you notice any sticking add a couple of squirts. You want enough oil in the case for the gears to pick up but not so much as to spray out by the engager. The gear box will always make some noise this is due to straight cut gears.
     
  4. fetor56

    fetor56 Guest

    Quite interesting....can u post a pic please of where u drilled the hole and any other info u feel might help. :cool:
     
  5. nsideus

    nsideus Guest

    What I use in this gearbox is a 50/50 mix of gear oil and transmission stop leak. I began drilling the hole after I had to take the gearbox apart to free a stuck clutch when using a grubee recomendation to use grease. Learn from this site alot of us have screwed up enough to know. The silicone seal was when I found out the gearbox leaks.Drill a hole apx.1/8 and tap (you can make it whatever size works for you) make sure to use a short screw that will not touch the clutch one that just makes it through the housing, check before sealing. Use a squirt type oil can.
    The hole doesn't have to be in this exact location but in a place where the oil has a chance to get on the clutch plates. On my rack mount the hole is located near the top of the raised portion of the gearbox or to the left in this picture.
     

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  6. fetor56

    fetor56 Guest

    Thanks nsideus,appreciated man.
     
  7. use 5oz no more of oil !!!!!
     
  8. HoughMade

    HoughMade Guest

    Is that so the gears just dip into the oil, but are not bathed?

    On some implements I have, there is a fill hole, a drain hole and a level hole. With the level hole, you fill the thing up until the oil just starts to ooze out- then you know you have the correct level. i was thinking of doing the same here. Any thoughts?
     
  9. Irish John

    Irish John Guest

    Gearbox grease

    That picture by nsideous shows a hole in the gearbox outer casing. Presumably it squirts oil on the gear wheels but not the centrifugal clutch behind it. Are you talking about the drive sprocket engager mechanism behind the final drive sprocket or the centrifugal clutch?
    I took out all the gear wheels and applied a good coat of MPG Universal Marine Grease made by Rock Oil Company from the UK. It's a white tacky lithium based grease and I reckon it's the best however I haven't started my motor yet and am still assembling the bike. I wouldn't want to go with a wet gearbox because I'd have to replace the silicone sealant every time I changed the oil or took off the gearbox cover. I found this grease to be superb on the HT engines gear sprockets - way better than anything else.
    Am I mad or should I ditch the grease and go with a wet gearbox. It's easy to apply the grease - takes 30 minutes to apply it to every single cog.
     
  10. Irish John

    Irish John Guest

    Please can you explain how the oil gets to the centrifugal clutch plates when is is behind the gearbox? Also what type of silicone sealant do you use and do you have to replace it each time you take the cover off the gearbox?
    I still want to try my tacky white marine grease which was so good on the HT gears. If its no good I'll reconsider using oil.
    Thanks nsideous,
    Irish John
     
  11. Irish John

    Irish John Guest

    Can someone tell us non-imperial measure guys how much is 5oz?
     
  12. azbill

    azbill Active Member

  13. HoughMade

    HoughMade Guest

    This is not for mixing.

    That would be a hair under 150 ml.
     
  14. azbill

    azbill Active Member

    oops :(
    I guess I kinda jumped the gun :lol:
     
  15. nsideus

    nsideus Guest

    I try to locate the gearbox hole where the clutch bell housing holes are this gives it and opportunity to reach the clutch plates. With the gearbox engaged rolling the bike backwards rotates the bell housing. Oil the clutch plates and inside the bell housing before assembly. My first gearbox I used grease and had to take it apart because it kept sticking and I greased the clutch well. I am not saying this is the way to do it it just has worked for me. I have been using high temp rtv silicone gasket maker on another gearbox I have not had to take it apart but I would probably need to replace the silicone if I do.
     
  16. Irish John

    Irish John Guest

    How much does it leak if you don't use silicone gasket sealant? I just don't want all the hassles of an HT with a 4-stroke. Incidentally if you factor in the amount of engine the 4-stroke is probably cheaper than the HT. It is certainly better value.
     
  17. HoughMade

    HoughMade Guest

    I don't know how much it would leak without silicone, but that is why I would put in a drain hole and a hole to check the level as well. That way, you would not have to take the cover off to drain.
     
  18. Irish John

    Irish John Guest

    Thanks HoughMade but how do you make the drain hole leakproof? Also to what depth in the gearbox do you fill the oil up to? Half way up the gear wheels? There'd need to be a good depth for the oil to get splashed around to all the cogs.
    Does the centrifugal clutch really need lubrication?
    Lastly, how do you drain the oil from the engine without turning the bike upside down?
     
  19. HoughMade

    HoughMade Guest

    How far do you fill it up? I don't know- I have run mine dry so far. However, on general priciple, I would think it needs only have the largest gear dip into the oil- the oil will climb to the rest of the gears....provided conventional oil is used...and I would not see a reason to use anything else. Synthetic gear oil does not climb as well which is not a concern in a pressurized oil system, but is a concern when lubrication requires the oil to cling and climb. I personally do not see a need to bathe the clutch, but I would like oil on the gears. Others want the clutch to run in the oil....so far, I do not think there is any consensus.

    As for making the drain hole leak proof- the same way a drain plug on a car does not leak- drill the hole, thread it, and plug it with a bolt, washer and rubber washer.
     
  20. Irish John

    Irish John Guest

    Thankyou so much HoughMade. I reckon I'll try it with my gears greased for a short while to see and then I'll do the oil bath idea. I'll keep the clutch dry to see hopw that goes. Any problems and I'll go for the oil.
    How are we expected to drain the engine oil (not the gearbox oil) from the motor sump? It has to be done rather too frequently and I suspect the every 10 hours is a bit of a ridiculous statement from the manufacturers. Every 10 hours is every 250km and that is about once every 8 days for me which makes things very labour intensive. Especially if I have to take the motor off to drain it,
     
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