40 series is "clunking"

[whatto]

so my 40 series torque converter (Chinese) ever since I have gotten it has been clunking. Disengaging and engaging when weight in introduced. I have checked the belt size, alignment and all of the above. is anyone willing to help or have any insight to this problem? I am out of ideas unfortunately.

also would greatly appreciate if someone could tell me what belt size I need too:
7 1/2 inch pulley
center to center is about 8.38 inches
I am currently running a 203786 belt (Chinese)

then my second question was I don't know what gear ratio I should be at. I have a 13hp engine on 20" rear tires with a ratio of 1:4. The load plus the kart is roughly 250kg or 550lb.

this might be a reason to why its clunking...but I don't have any ideas. I did run a 30 series intitially however it had nothing problems except from excessive belt wear.

 

[panchothedog]

Show us a picture of two clutches. Especially a good side shot of the center section of the driven clutch. Very likely that you need a reverse wound spring. Nothing wrong with it being a Chinese unit, they all are. Most of the non kart vendors aren't even aware of the need for a reverse wound spring. We can tell from a picture.

 

[whatto]

I had thought as long as they are opposite ways it would fix itself? unless it just applies to the driven part of the converter?

 

[panchothedog]

Your driver ( on the engine ) is fine reversed like that. The driven needs the reverse wound spring. The points on the outer most piece are sitting behind black plastic stops. They need to be on the front side. Installing the reverse wound spring takes care of this. You'll need a good set of snap ring pliers.
OMB Warehouse sells them for about $15. Probably other places also. That's where I bought mine. BTW your belt looks fine.

 

[Denny]

Do not ride it anymore until you replace the spring in the driven with the correct reverse wound spring! GoKart Supply has Great tutorial on the CVT systems.

 

[whatto]

thanks heaps! Would it be okay if I turned it around?

 

[Denny]

Only if you got rid of the back plate and went to a jack shaft.

 

[whatto]

why wouldn't it work with the backing plate?

 

[BaconBitRacing]

why wouldn't it work with the backing plate?

No room for movement, no TC action.

 

[Denny]

The primary would need to be moved away from the engine about 6”. The crankshaft ain’t that long!

 

[panchothedog]

whatto. Replacing the spring is not hard at all. 10 to 15 minutes work. I am a
75 year old man, who has easily lost half of the hand strength I once had. I replaced mine by myself. Your kart will be a whole different animal once the clutch is working as it is supposed to.

 

[whatto]

what if I had created a jack shaft for it and made it face the other way? Similar to the photo attached?
in other words it should look like this?

its just that getting the reverse spring would be too long as I am in Australia and would cost the same as if I were to make the jackshaft.

 

[Denny]

Build the jackshaft! What you show is the correct way it should be set up!

 

[whatto]

So I made the jackshaft and gave it a go. Within 5 minutes my spring and button broke.

 

[Denny]

Yea, you beat it up to badly.

 

[whatto]

does anyone know what this had happened?

 

[Denny]

It’s from running the clutch in the wrong direction and it slamming open.

 

[whatto]

So if I get a new spring, and run it the correct way now (facing the engine), nothing should be wrong with it? If someone could send me an accurate video or type a description on our to install the spring properly that would be amazing.

 

[Denny]

GoKart Supply has a great tutorial on CVTs. Just look in their clutch section.

 

[panchothedog]

You can only put the spring on one way. It's just like the damaged one that you just removed. Only wound in the opposite direction. Not hard to figure out. Buy it, and it will solve your problem.