Rupp Roadster2 - ReMod

[Wojo]

Hello - I am farting with my 71 Roadster that was given to me as a birthday present in 1973. I put a Clone on it with a carb and exhaust tube and got it started. I need some guidance on the TQ coverter, jack shaft and gearing. I want to do it right the first time. I'm a former helo mechanic and we like things to work. Looking to keep the clone under the 11HP mark. Comet 40? What about the jackshart and gearing for trails with a max speed of 40 with a 225 pound rider?

More of a pit / camping bike. Holy crap is that unbaffled torque tube LOUD! I have a perferated butterfly plate that flips to full open. I am probably going to want to muffle that a bit. And I still have my 78 Bonneville with straight pipes and I think the Rupp is louder.

So far...I rebuilt the forks / head bearing replaced. New tires, painted the frame red / tank black, removed the headlight / tail-light.

 

[RobertC]

Hello @Wojo ...welcome to the Oldminibikes.com forum !

Cool bike. Very cool picture from "back in the day".

Tell us, where is the original 4hp tecumseh engine ?

Keep us posted.

Enjoy the site !

 

[GustoGuy]

Hello - I am farting with my 71 Roadster that was given to me as a birthday present in 1973. I put a Clone on it with a carb and exhaust tube and got it started. I need some guidance on the TQ coverter, jack shaft and gearing. I want to do it right the first time. I'm a former helo mechanic and we like things to work. Looking to keep the clone under the 11HP mark. Comet 40? What about the jackshart and gearing for trails with a max speed of 40 with a 225 pound rider?

More of a pit / camping bike. Holy crap is that unbaffled torque tube LOUD! I have a perferated butterfly plate that flips to full open. I am probably going to want to muffle that a bit. And I still have my 78 Bonneville with straight pipes and I think the Rupp is louder.

So far...I rebuilt the forks / head bearing replaced. New tires, painted the frame red / tank black, removed the headlight / tail-light.

I used a Chinese 20 series comet clone and it works well. I have a Predator 212cc non hemi with a billet rod billet flywheel Mukuni VM 22 carburetor. I never had HS40 engine on it. I bought a Robertson torque tube exhaust with the swivel baffle in it and once I turned it open I found it was too loud so I run it with the baffle in place. The bike is not little kid friendly or even novice friendly and it hits pretty hard of the bottom so I will only allow a select few to ride it. I made the mistake of letting my wife's nephew ride it and despite telling him not to gun it he Supermanned it and flipped the bike and smashed the fender and tailight and bent the seat pan up and shoved it to the left about 1/2 inch. He told me that he had a 125cc Yamaha dirt bike when he was younger so I mistakenly thought he could handle the bike.

 

[Wojo]

Hello @Wojo ...welcome to the Oldminibikes.com forum !
Cool bike. Very cool picture from "back in the day".
Tell us, where is the original 4hp tecumseh engine ?
Keep us posted.
Enjoy the site !

Thanks. This is my fourth mini bike...home made death machine, proper simple mini-bike (below circa 1971), Rupp Scrambler, this and then 125 / 250... 750 / 1450 / 650 / 200's.
I have all the original equipment boxed and tucked away. A buddy of mine after his enlistment wound up having a small engine / equipment repair shop. I asked about doing a resto on the original motor. He looked into parts and labor and essentially told me he wouldn't take the project or my money. He steered me to the Clone against my heart. I know it is essentially a unicycle after my test run. I left the governor on for now.

 

[Wojo]

I used a Chinese 20 series comet clone and it works well. I have a Predator 212cc non hemi with a billet rod billet flywheel Mukuni VM 22 carburetor. I never had HS40 engine on it. I bought a Robertson torque tube exhaust with the swivel baffle in it and once I turned it open I found it was too loud so I run it with the baffle in place. The bike is not little kid friendly or even novice friendly and it hits pretty hard of the bottom so I will only allow a select few to ride it. I made the mistake of letting my wife's nephew ride it and despite telling him not to gun it he Supermanned it and flipped the bike and smashed the fender and tailight and bent the seat pan up and shoved it to the left about 1/2 inch. He told me that he had a 125cc Yamaha dirt bike when he was younger so I mistakenly thought he could handle the bike.

Was this on a Rupp platform? What did you for a base plate? I ordered this kit and the dimensions were off and I had to return it. https://www.OldMiniBikes.com/torque-converter-3-4-bore.html

I tried to modify a brace / bracket and use the OEM TQ belt cover, and I don't like the fit. If it goes down on the that side, we were going to have a rubbing situation that I don't want.

 

[GustoGuy]

Was this on a Rupp platform? What did you for a base plate? I ordered this kit and the dimensions were off and I had to return it. https://www.OldMiniBikes.com/torque-converter-3-4-bore.html

I tried to modify a brace / bracket and use the OEM TQ belt cover, and I don't like the fit. If it goes down on the that side, we were going to have a rubbing situation that I don't want.

Yes. A resto-mod Rupp Roadster 2 with hydraulic rear shocks and Suzuki K10 Motorcycle fork on the front wheel. The rear secondary has a larger diameter on the 20 series so I modified the Rupp TC cover and it fits well now.

 

[manchester1]

Nice you got it going but I would of tried to keep it original. I would be interested in the original motor if you like to sell it. Have fun .

 

[Cuda54]

Many years back we used a bottle jack and shoehorned a Tech 7hp into the stock frame. Had to use the short plug to get it in there. My boys liked to spin the tire in the dirt and do wheelies too. It would wheelie with me on it too. I sold it but I did get another one and I have a 7hp to go in it. I have a new seat cover and foam it is green but the boys want it red like the old one. The grandsons are into hot rodding the 212 mini bikes.

 

[GustoGuy]

Many years back we used a bottle jack and shoehorned a Tech 7hp into the stock frame. Had to use the short plug to get it in there. My boys liked to spin the tire in the dirt and do wheelies too. It would wheelie with me on it too. I sold it but I did get another one and I have a 7hp to go in it. I have a new seat cover and foam it is green but the boys want it red like the old one. The grandsons are into hot rodding the 212 mini bikes.

No bottle jack required to fit Predator 212cc In a Rupp. Plus I have billet flywheel and billet rod and Mikuni.

 

[ZR9B]

i had the same gas cap....cool pic

 

[ole4]

I have a similar build and use a comet tav 30 with no changes to it. Not sure of the gearing but I can take pics, it has a quick-change rear sprocket but I don't remember how many teeth,

 

[Cuda54]

The 212 to me is too wide the 7hp fits like the 4hp does. And has the same power plus it can be built too. I also have a 10hp with electric start and charging.

 

[joshua. c.]

so what is wrong with the old motor? is it just not running or is it smoking? missing parts? black widdow motorsports now carries the 20 over piston for the hs40 motor and dyno cams can re boar the block for you.