GX390 CVT Help

[RustyShackelford]

I'm trying to find a drive clutch that properly fits a Honda GX390. The motor has a 1" diameter shaft with a 1/8" deep keyway. My problem is, every clutch I find online has a key machined in as part of the bore, but the key is measures 1/4W x ~1-1/4L x 1/16H. Leaving 1/16" of empty space in the keyway between the bottom of the key and the bottom of the keyway.
So, there's slop in the keyway that will eventually damage the keyway and shaft.
Can anyone point me towards a CVT drive clutch that has a 1/8" deep key or, even better, rather than incorporating a key into the bore, just has a 1/8" keyway in the bore?

 

[Denny]

File fit from larger key stock.

 

[RustyShackelford]

HI, Denny. The issue is the key is too small. The width and length are right, but the integrated key machined into the bore of the clutch is too shallow to reach to reach the bottom of the keyway in the crank.

 

[Whitetrashrocker]

As long as it connects the sides we'll and you tighten the bolt you should be fine.
If that key was .125 exact height you would have some interference issues with tolerances.
Send it.

 

[Master Hack]

I have the usual ebay/amazon CVT onna GX 390 l would have to look, but whatever it has works fine. I’m putting a bit more than 13 hp through it as well.
ls the key in the clutch look stamped (ramped ends) or machined (square end)?

 

[ezcome-ezgo]

McMaster-Carr

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Just find a key that will work. If it isn't here, let me know.

 

[ezcome-ezgo]

Or perhaps you need a step key, or offset key.

 

[bob58o]

If every clutch is one way and you want to go the other way, maybe you are going the wrong way? Or you might have to pave your own road.

My advice… put the cheap 40 series driver on it and forget about it.

In the almost 10 years I’ve been on forums like this, I never heard anybody bring up this as an issue, so it’s probably not an issue.

Solving problems that don’t exist has upper management written all over it.

 

[ezcome-ezgo]

It's the Suits!

 

[65ShelbyClone]

There's no way for there to be slop from a gap at the bottom of the keyway because there is no radial movement.

HI, Denny. The issue is the key is too small. The width and length are right, but the integrated key machined into the bore of the clutch is too shallow to reach to reach the bottom of the keyway in the crank.

They're all like that; it's a non-issue with proper installation. If it really bothers you though, look for a "heavy duty" centrifugal clutch. They have a solid drum with no holes and all the ones I saw take a separate 1/4" square key.