What Kind Of Pulley Is This???

[71_Bronco 1,072]

Was working on my Wisconsin S7D today, taking off the carb, and removing the old exhaust (making way for a Jim Kemp stack).

 

I was looking at the pulley on the output shaft, and I can't figure out what I'm looking at.

 

The pulley spins freely, without the crank spinning. Maybe a centrifugal clutch of some sort?

 

I also can't see any way to remove this? I don't see any set screws or anything like that. And there are no tapped holes on the face, to pull with a puller (like a regular pulley).

 

Help please.

 

 

[ebinmaine 72,669]

1 hour ago, 71_Bronco said:

Maybe a centrifugal clutch of some sort?

 

I believe that's it. 

 

 

I'd theorize it needs to be pulled from behind the pulley but I could very well be wrong. 

[WHNJ701 4,165]

3 jaw puller should work, spray it all up with pb blaster

[71_Bronco 1,072]

If the pulley size was the same as what I needed (2-1/2" diameter), would it be an issue to run this pulley?

 

I'd be running it at full power anyways to get it to oil itself properly, so I'd think it would be engaged. Only issue would be if it slipped while engaged, and didn't give the gear box full power.

 

I'd also have to check clearance with the stock belt guard to see if that flared end would fit without issue.

 

Thoughts?

 

Edit: if this is the correct, stock clutch from Wisconsin, then the engagement is at 1,700 RPM according to what I've found.

Edited September 20, 2020 by 71_Bronco

[71_Bronco 1,072]

Found this online, showing what the clutch looks like.

 

According to this, the outer front "cover" should be held on by screws, but I don't see any screws on mine.

 

I'd hate to try to pull this off while there is some kind of set screw holding it on.

[ebinmaine 72,669]

I'd try to run it. 

Slippage won't be an issue if it's working right. 

[oliver2-44 10,715]

I'd buff the front off good with a wire brush or emery paper and see if there are some recessed screw heads hiding.

[Lagersolut 742]

Diagram has the set screw going in on an angle from the face . 

 

I blew up the 2nd picture showing  the face I can see what appears to be a round indentation at about 5 o clock  ... could that be your set screw access covered with a cap plug to keep the dirt out ? 

 

 

[Lagersolut 742]

It's very faint but right here  - take a scribe or a small punch is this a cap plug covering your screw ?

 

# 6 on the diagram

 

Edited September 21, 2020 by Lagersolut

[71_Bronco 1,072]

I brightened the photo of the face. I apologize for the poor picture, the shed was a little dark and I was in a hurry. I'll do a little more inspecting tonight.

 

There definitly looks like there is something there on the face, but I dont know exactly what it is. I'll also check the pulley area again to see if I missed something.

 

 

[Pullstart 66,723]

Nick, I’m one more vote for leave it be.  Once those things grab, they don’t like to let go without slowing up.  That one looks like it’s much more stout than say a go-kart clutch!

[WHNJ701 4,165]

It's gotta come off, while we are all waiting you should be soaking it pb blaster.  Take a drill with a wire wheel to it

[peter lena 9,271]

71-BRONCO, i agree with others on the centrifugal clutch set up , that was typical old school set up, i would also use a 2 piece puller flange behind that to pull it off, the strength of that is directed to the center of the pulley mount , the 3 piece pulley removal arms ,are more likely to break the inner belt grove. it would be nice to save that old type clutch and reuse it on something else. pete 

 

[71_Bronco 1,072]

Crisis averted.

 

I did some more looking, and the front part was not a cover, meaning it is an aftermarket clutch.

 

 

Then I started looking it over, and found at the very back, a small set screw. I was a little nervous it would strip, as it was only a 1/8" hex, and it was a little loose on the hex key.

 

 

Luckily, it popped right out. Id say it was slightly more than finger tight. Sigh of relief.

 

Then I grabbed my big 3-jaw puller, and put it behind the clutch portion of the pulley (after spraying with PB Blaster from the end and into the set screw hole). Put a ratchet on the puller... and it started moving right away. Came off without any issue. It was a little snug, but didnt fight. There was oil on the shaft and on the inside of the pulley bore, so im guessing it wasn't a press fit at all, and wasn't "fused" to the crank.

 

 

I checked the pulley size compared to the stock 3-groove pulley. The clutch is much bigger than the WH one. Probably would have made the Lawn Ranger go faster, but the belt guard probably wouldn't fit.

 

 

Lastly, since I had the 3-groove pulley on hand, I tried it on the crank to see if it was the right size. Slid on nicely until it hit the key, and then gave a little resistance. The key is probably slightly larger than the keyway, causing the bind. Looks like I got off the hook easy with this one.

 

 

On a side note, the parts are coming in for this. Got a few new gaskets, new plug, NOS Wisconsin points & condenser, new air filter. I also pulled the head, and everything looks good. Clean cross hatch on the bore, and not much carbon build up under the head.

 

Think I did good for $100.