Rupp Torque Converter Advice

[caver1510]

Trial and error are your best bet here. The 3 holes allow for different settings of the wound spring tension. The lighter the tension the faster it will shift out into high gear. For a light weight rider on flat ground that would have the highest top speed. For a heavy rider, the light setting may now let it shift as high for top speed. It may try to hold it at a lower gear ratio.
Try each hole and determine which one works best for your riding style and conditions. If you climb a lot of hills then the tighter spring setting would probably work best. Flat paved surface riding ???
Experiment with it

Danford1

Any suggestions for keeping the end of the spring in one of those 3 holes? No matter which hole I use, it seems to want to slip out. Seems it would be better if the end of the spring would be a little longer.

 

[danford1]

Any suggestions for keeping the end of the spring in one of those 3 holes? No matter which hole I use, it seems to want to slip out. Seems it would be better if the end of the spring would be a little longer.

I wonder if your spring has a broken end. Mine stays put easily...

Danford1

 

[Ruppelstiltskin]

I think you need a new spring there caver. I had mine off but the spring didn't want to come out on mine like it was peened a little bit so I left it. If it sticks through at all you could try peening it.

I installed my new Comet driver and the 3/4 belt. I can now throw myself off the bike/wheelie anytime I want from a stop WEEE WEE WEEEEE said the piggy. GPS says I lost 2 mph on the top end. I'm hoping the Comet driven will improve that. I was about to have the driven installed come to find out I didn't research that part and assumed it was also 3/4 diameter and turned out to be 5/8. Also get to pay a hefty 20% restocking fee since they drop shipped it (Of course that was not disclosed when I placed my order :doah: )

 

[danford1]

I think you need a new spring there caver. I had mine off but the spring didn't want to come out on mine like it was peened a little bit so I left it. If it sticks through at all you could try peening it.

I installed my new Comet driver and the 3/4 belt. I can now throw myself off the bike/wheelie anytime I want from a stop WEEE WEE WEEEEE said the piggy. GPS says I lost 2 mph on the top end. I'm hoping the Comet driven will improve that. I was about to have the driven installed come to find out I didn't research that part and assumed it was also 3/4 diameter and turned out to be 5/8. Also get to pay a hefty 20% restocking fee since they drop shipped it (Of course that was not disclosed when I placed my order :doah: )

Where you using the Comet driver with the stock Rupp driven?

Danford1

 

[Ruppelstiltskin]

Yes Comet driver, Rupp driven + 3/4 Comet brand belt

 

[danford1]

Yes Comet driver, Rupp driven + 3/4 Comet brand belt

What belt length did you end up with?
I have two Rupps and at least one could use a Comet driver... Seems like a decent way to fix up a worn Rupp clutch.
What was is the part number of the driver clutch you bought?
Thanks
Danford1

 

[Ruppelstiltskin]

Sorry for the late reply. Driver :219559A. Belt you need to look at the Comet chart. I have a Honda engine so my belt may not be correct for yours. You have to measure center to center from your drive to driven and get the closest size on the chart that matches your 6" stock driven.

 

[danford1]

I think I'll order up a 20 series driver from Ebay. I saw this one for $44.70 with free shipping. Go Kart Mini Bike 20 Series Torque Converter Clutch Driver 3/4" Bore Comet Manco | eBay

You said you lost 2 mph when you used the comet driver and stock Rupp driven. What were your mph readings?
Also you mentioned your shafts were 6 7/8" apart. What 3/4" wide belt did you use?

Danford1

 

[Ruppelstiltskin]

The one on ebay is the China made knock off copy of a comet. I heard they work fine but I payed up for the genuine usa parts because I'm trying to support the home land.

Belt part 203578A. My crank center could be different than yours though, just do a simple measure. I Got 34 mph with the old stuff and 32 with the comet. There may have been more mph potential if I had a tighter belt on the rupp driver though, hard to say. I have plans to possibly change the jack shaft sprocket later to get more top end out of it. No idea what engine rpms I'm getting at this point either. Planning to move up to a bigger stronger motor in future.

 

[danford1]

The one on ebay is the China made knock off copy of a comet. I heard they work fine but I payed up for the genuine usa parts because I'm trying to support the home land.

Belt part 203578A. My crank center could be different than yours though, just do a simple measure. I Got 34 mph with the old stuff and 32 with the comet. There may have been more mph potential if I had a tighter belt on the rupp driver though, hard to say. I have plans to possibly change the jack shaft sprocket later to get more top end out of it. No idea what engine rpms I'm getting at this point either. Planning to move up to a bigger stronger motor in future.

Thanks,
Mine measures 7" center to center from engine to jack shaft.

Did you replace the driven yet with a Comet also?
If so, did you have any alignment issues getting it to work right?

Danford1

 

[Ruppelstiltskin]

I haven't ordered the correct driven yet, got caught up on one of my car projects this week

 

[danford1]

I haven't ordered the correct driven yet, got caught up on one of my car projects this week

Any updates on this old thread? I'm restoring a couple Rupps now and might be buying clutches and belt.
Please let me know what you ended up with and how it worked out.

Danford1

 

[joebiodiesel]

This week I'm going to buy one of those $40.00 EBay clutches for the driver on my Roadster 2. I'm going to use my original Driven Clutch and a 5/8" belt. I'll drive it to see how it goes. Then I'm going to try cutting down the clutch on my lathe to fit a 5/8" belt instead of the 3/4" belt you are supposed to use with them. It'll take a few weekends to get it done, but I'll let you know how it goes.
Joe

 

[danford1]

In my opinion... it is much easier to shim the secondary to use the 3/4" belt. All you need to do is add a 1/8" washer or spacer between the two pulley halves. I also think the 3/4" belt will hold up longer too.

My other thought/opinion is you will regain the 2 mph you lost. The 1/8" spacer will allow the secondary sheeves to open up more creating a smaller diameter resulting in more top end speed..

Danford1

 

[joebiodiesel]

In my opinion... it is much easier to shim the secondary to use the 3/4" belt. All you need to do is add a 1/8" washer or spacer between the two pulley halves. I also think the 3/4" belt will hold up longer too.

My other thought/opinion is you will regain the 2 mph you lost. The 1/8" spacer will allow the secondary sheeves to open up more creating a smaller diameter resulting in more top end speed..

Danford1

That sounds like it would work too. Are you going to give it a try? I've already got a new 5/8" belt. I've also got a lathe to turn down the shaft and bushing. Maybe I'll try cutting the shaft. If I have belt problems it would certainly be easy enough to shim them both.
Joe

 

[Havasu Dave]

That sounds like it would work too. Are you going to give it a try? I've already got a new 5/8" belt. I've also got a lathe to turn down the shaft and bushing. Maybe I'll try cutting the shaft. If I have belt problems it would certainly be easy enough to shim them both.
Joe

Joe, I used spacers on my Powell driven- two different bikes actually- for the same reason. I was always worried I'd have some issues with it, but I never did. Loc tite blue.

If I had access to machine equipment however, I would have preferred turning them.

 

[joebiodiesel]

Joe, I used spacers on my Powell driven- two different bikes actually- for the same reason. I was always worried I'd have some issues with it, but I never did. Loc tite blue.

If I had access to machine equipment however, I would have preferred turning them.

That's very cool. Looks easy enough. If I didn't already have the belt I would certainly go that route.
I love the pic of it. That's great.
Joe

 

[joebiodiesel]

I got my 20 series drive clutch today and installed it. It is set up for a 3/4" belt. I used a brand new 5/8" belt from Black Widow Motorsports. Set my driven clutch up with the spring in the center hole. It was terrible. You had to rev it a lot in order to engage it, and even then it slipped like crazy. I tried several different belt tensions, including making it too tight. It never stopped slipping badly.
I double checked my top RPMs, and they are just a tick under 3600 at full throttle. Top speed was never over 15 mph and it wouldn't pull any kind of incline at all.
Tomorrow I will take an 1/8" out of the center to see if that helps. If it fixes it, I sure wouldn't recommend using one without cutting it down. With a new belt and proper tension, it just doesn't work.
Joe

 

[danford1]

The 20 Series Comet driver needs a 3/4" belt or it will slip bad and burn the 5/8" belt.
Let us know how it works after you take 1/8" out of the center.

Danford1

 

[joebiodiesel]

Once you machine the center of the clutch you also have to machine the stepped washer under the retaining bolt. Once you're done with that it works just fine. The clutch definitely likes higher RPMs before engaging. I bumped my governed speed to 4k. Now it goes just fine.

Joe