GruBee Clutch Key Way wrong size

jimraysr

New Member
Apr 19, 2008
78
0
0
Glendale, AZ
I have a complete frame kit for a Honda GXH50 plus an extra GruBee transmission.

Both clutches have the wrong size keyway cut in them.

The Honda engine has around a 3/16" key slot. (4.7mm)

The clutch bell housing bushing has one that matches the engine but metric keyway (4.6mm) and key (4.55mm)

That all works, the bell housing bushing turns wt. the engine and the key seems to be close enough to both the engine shaft and bushing not to cause a drive problem.

Having said that, the two clutches both have a 4.35mm keyway. They came from different dealers 2000 miles apart!

So I assume others have had the same problem? If the dealer doesn't have a clutch with the proper keyway, you are SOL. It seems when an importer buys a container of these kits, it is As is, Where is and no warranty from China?

I am still looking for a good solution. Have not found anybody that says they can cut the slot to the proper width. The 4.35mm needs to go to a 4.55mm or .1mm + from each side to keep the slot centered

Any suggestions or fixes will be appreciated. I don't feel comfortable with using a file to widen it. With an engine that turns 7500 rpm and the way the load comes on and goes off the drive train, I think a little slop could cause problems?

Jim
 
Last edited:

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
If it's only .1mm each side, I'd go ahead and do it with a file if you are good with a file, otherwise you may have to take it to a fabrication shop or motorcycle shop and have it done.

You also said this- "That all works, the bell housing bushing turns wt. the engine and the key seems to be close enough to both the engine shaft and bushing not to cause a drive problem." So then, what is the problem?

Maybe none?
 

jimraysr

New Member
Apr 19, 2008
78
0
0
Glendale, AZ
What I was saying was the engine shaft and the bell housing bushing plus the key were all OK. The clutch isn't OK as the key won't fit into it to drive the bike. Sorry if I wasn't clear.
Jim