New (old) Rupp - need help to id; engine; clutch

[Denis Kefallinos]

My name is Denis Kefallinos and I just picked up this Rupp from a trashpile! All it appears to need to get moving safely is an engine, clutch and front brake lever. Might need some exhaust re jiggering as well. I need some parts and I have some questions:

1. Can you identify what model Rupp this is? I'm thinking Enduro..

2. Engine - I've been looking at 4 hp Tecumseh Sport replacements. I think I read on a website that the 4 hp will work without the carb leveling piece. Is that true?

Also, will the exhaust presently on the bike fit with the 4hp, or will I need to fabricate new?

3. I need a clutch. Assuming I buy a new 4 hp Tecumseh, what Comet clutch can I use?

4. Which belt? 5/8"? 3/4"?

Thanks!

Denis

[RuppRider]

Hey Denis, your bike is a 70 model Rupp "Roadster" as it has 10" wheels, headlight & tail lights. I have one just like it that I restored. You can see it on www.ruppbikes.com. If you've never been there, then go. As far as the clutch, you need a variable pitch type that comes on it. It changes ratio as the bike speeds up. A centrifugal (sp?) clutch for a belt will not give you give you the power at take-off & top speed like the original parts. They can be found on Ebay occasionally or contact Joe at J&L Sales. He has many parts, some NOS & repop. The later model motors seem to work on the bikes, but I don't know how well the float in the carb works on the slant. There are adapters to level it out. The exhaust & intake ports are swapped on the later motors so your exhaust will not fit up well. Hope this helps.

[T-Mack1]

Denis,
1. Rupprider answered aleady. Enduro's & Scramblers did not have lights. Scramblers did not have front brakes.

2. I ran a Toyoco minibike (Rupp clone) without the slant intake. It ran fine, but....it was less angled than the Rupp's. 15 deg vs 20 something deg's. (see: www.users.fast.net/~tommack/toyoco-minibike.htm).
J&L Vintage sales (http://www.jl-sales.com/) sells an aluminum block converter. Saw one at the minibike reunion, looked good. Smaller than it looks in Joe's pictures.
4 hp Tecumseh engines come with the exhaust/intake two ways. You need it with exhaust on flywheel/pull starter side for the exhaust pipe you have. I saw a new engine last year with the correct side. (confusing, I though new one were all the same). If you can't find it that way, Joe at J&L has conversion pipe. Not sure for the '70. Call him, he's very helpful.

3. I'm running Comet torque converter Clutches on our two Rupp's. Best prices for new (with warranty) TC clutch is at American Power Sport (http://www.apskarting.com/). About $50 last year (NEW!!).

4. Rupp's used 5/8" belts. The 5/8"clutches are hard to find. I saw one on ebay that someone had converted from the 3/4" ( I think it was Bob at Tired Iron). You can also convert the driven pulley to run a 3/4" belt by added a stop washer to keep it from closing all the way. One of my Rupp's is running this way. Actually runs better than the 5/8" belt. Washer size is: 1 1/4 " O.D., 13/16" I.D., and 1/16" thick. (you would think it should be 1/8" thick, but it has to do with it being a V-belt).
You will need the TC cover (big safety issue). The 1970's were 8" center to center of the pullies. The 71 & up were 7". They are not interchangeable. J&L has re-pro's.

J&L Vintage sales (http://www.jl-sales.com/) has all the parts you need if you want original. Some are rare, which means pricey.

t-mack
www.users.fast.net/~tommack/minibike.htm