4 - stroke Schwinn Stingray Chopper occ

Related to this post: https://motoredbikes.com/threads/pr...chopper-and-im-looking-for-some-advice.50872/

Donnor bike:

Since this is not being an standard build (as expected) I'm going to describe how I'm solving the issues that I'm having, I hope it will be useful for someone.

First thing, choosing the motor kit: after digging and asking around I decided to go for
I ordered this kit: http://www.bicycle-engines.com/49cc-4G-T-Belt-Drive-Complete-Gas-Powered-Engine-Kit.html
I didn't know if to get the 100 or the 80 tooth pulley, I asked on the chat that they have and.... I believe the person behind didn't know much about what she was talking about... I asked which configuration will be faster and she told me the 100 tooth... After checking the manual that comes with the engine, that is wrong, 80 has a "faster" ratio, 100 is for better hill climbing and torque. Because of this I ordered a smaller sprocket (36 tooth), I'll get a Engine rpm to bike wheel rpm ratio of 18, close to what you get with the 80 on the transmission and a 44 on the wheel (17.6).
[UPDATE]
After contacting BE, they are sending me a 80 tooth transmission to exchange with the 100 one, I don't have to pay for anything, amazing customer service!

Pieces I've ordering so far (updated on Apr 2018):
- 49cc 4G T Belt Drive Complete Gas Powered Engine Kit - 80 tooth transmission (from Bicicle-engines) (firt transmission was a 100 tooth by mistake, exchanged with a 80 tooth)
- 2 Piece Muffler "Poo Poo Pipe" Deluxe For 4 Strokes
- Flexible muffler tube (eBay)
- 36 tooth sprocket (Amazon)
- 40 tooth sprocket (Amazon) <- using this one
- Sunlite D-Cruiser Handlebar, 32" W x 13.5" H x 7/8" - Hi-Rise handlebar
- 2 x 2,5 inch U-clamps with nuts and washers
- Front wheel, being a 24'' back wheel with free-wheel to install disk brake
- Disk brake kit for free-wheel (BlueSunshine Front and Back Disk Brake Kit - 160mm For 80cc Gas Motorized Bicycle - Amazon)
- Front fork with suspension

First thing is holding the motor to the bike, the engine bracket that comes with the motor si not compatible with the frame, and indeed, there is no much room to play around in the frame, so I have to remove pedals, bike chain and the chain cover, after that still, really tight, so I cut a portion of the chain cover holder, like in the picture:

After thinking about different options, I come up with a solution, using the central part of the bracket drilling 4 holes (picture only has the first two) on each side of it, so I can use 2 u-clamps to hold it to the bottom part of the frame of the bike

After first try, looks like it is gonna make the trick, the round part of the u-clamp is kind of the same round that the frame, so it adjust well, on the other side, part of the unthreaded u is coming out of the bracket, so I need some washes or something, and of course, I'll have to cut the u, it is way too long.

So far Is what I did (as October 8th). I'll keep updating as I work on it.

November 5th update -> https://motoredbikes.com/threads/4-stroke-schwinn-stingray-chopper-occ.51001/#post-451003

Video of the first start of the motor (Nov/05) -> https://motoredbikes.com/threads/4-stroke-schwinn-stingray-chopper-occ.51001/page-2#post-451198

 

[dmopedMA]

I have to cut the choke plastic lever down on many 4-stroke builds.

The trick is to epoxy the lever back on, but if you can do that you can orient the lever however you want, like off to the side.

Just a tip ;-}

Thanks for the tip

Since you are around, any tip on how to bend the exhaust pipe? I got this one: http://www.bicycle-engines.com/2-Piece-Muffler-Poo-Poo-Pipe-Deluxe.html but it doesn't clear the frame. I was thinking just bending it using a vise to hold the muffler but I'm not sure if I should heat it up or something before.

 

[dmopedMA]

And here, how it starts and sounds with the stock muffler:

 

[Philandra Chambliss]

Thanks! 4-stroke are wider than 2-stroke so I believe is gonna be easier, still chalengy.

"Extendo click."

 

[dmopedMA]

Still around! winter is being hard in New England, but I'm starting to prepare myself to finish this bike.

Anyone with any tip of how to make this pipe to clear the frame? I'm not sure if I can just bend it...

 

[Frankenstein]

Is that for a 4 stroke? You can bend it yes. A pipe bender might be able to work on something that big, come to think of it a muffler shop should have a machine that could eat 1 inch steel pipe for breakfast, I would believe the guy could bend it in just a few minutes to the exact shape you need. Cut a full size cardboard replica of the path you need, or better yet just bring both to him and ask him to bend it into place so he can have the satisfaction of bringing it together.

 

[dmopedMA]

Is that for a 4 stroke? You can bend it yes. A pipe bender might be able to work on something that big, come to think of it a muffler shop should have a machine that could eat 1 inch steel pipe for breakfast, I would believe the guy could bend it in just a few minutes to the exact shape you need. Cut a full size cardboard replica of the path you need, or better yet just bring both to him and ask him to bend it into place so he can have the satisfaction of bringing it together.

Thanks! I tough I'll be able to do myself, but it's true that maybe profesional help will be the right choice.

 

[Frankenstein]

Thanks! I tough I'll be able to do myself, but it's true that maybe profesional help will be the right choice.

His press won't blue the chrome on the muffler unlike heating to red hot with a torch, if it was raw steel I probably wouldn't have mentioned it since i wouldn't be concerned about the finish lol.

 

[dmopedMA]

Brief update again:

I ordered a new front fork (I'm not sure if I'll regret it...) like this one:

It's almost 2 inch shorter than the original one, but it's the closest I found for a good price, I'll update with pictures of how it looks like installed as soon as I get it.
Pros:
- Disk and V-brake compatible
- Shocks for smooth ride
- Heavy duty fork
Cons:
- Look (lack of flames? ;-) )
- Shorter fork

Since it's a little shorter than the original one, I want to try a 26in wheel on it, just for the shake of how it looks and it will give me back the front of the bike to the same high...

I'm planning on rebuilding the front wheel (24 or 26 in, not sure yet) to put a disk hub on it, so I'll add front disk brake to the bike.

 

[lee]

Here's a tip for you that will help the looks of your bike and engine. Paint the red engine side cover either satin or flat black, I did on mine really helped the looks. a cheap upgrade in price.

 

[dmopedMA]

Updates:

Pedals pointing forward, big screw passing the pedal hub.

Still waiting for the front fork.