Finished OCC Chopper build

Discussion in 'Stretch Cruiser & Chopper Motorized Bicycles' started by gstrope, Apr 27, 2017.

  1. gstrope

    gstrope Member

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    This motorbike is conversion of a Schwinn OCC Chopper Bike into a motorbike. I started with the bicycle, took it apart and stripped it down to the bare metal and refurbished the chassis with new paint and cleaned and adjusted of all the bearings. I then added new tires and new brakes. Next the motorized conversion took place by building a custom motor mount and adding a new 80cc Flying Horse Bullet Train 2 Stroke Bicycle Engine. This engine allows the bike to be a full motorbike without the need of pedals. Other OCC Chopper conversions make you pedal the bike first to start it. This version you just hit the starter button, twist the throttle and go.

    This engine has an automatic centrifugal clutch. There are two different starting methods, electric start with an onboard motorcycle battery or backup pull-starting if for some reason the battery is dead.
     

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  2. KCvale

    KCvale Active Member

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    Nice clean build but you need more brakes.
    Good luck with BT80 electric start engine, mine didn't last 20 rides before it couldn't be started, and even after I got replacement parts it only lasted ~10 more starts.

    Best of luck with it, and get some darn brakes silly!
     
  3. xXNightRiderXx

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    You need front brakes more than your rear. The front is where your stopping power should be. Saves your rear tire which you need to get anywhere, plus the front brake will stop you in half the distance your rear brake will, so if you use both, you effectively cut your stopping distance down to a fourth. This is about 1/16 the distance a car needs. You should fit an alternator on there if you can. I'm sticking a Chevy blazer alternator on my 212. Mostly so I can have my music, but also for bright enough lights and a full charging system. My 670cc build will have the same alternator, but with a lot more on it.
     
  4. gstrope

    gstrope Member

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    I plan on adding a front brake. What kind of problems did you have with the Bullet Train engine?
     
  5. gstrope

    gstrope Member

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    This motor already has an alternator built in. I do plan on adding a front brake. I will post pictures when I do.
     
  6. gstrope

    gstrope Member

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  7. pedalchopper

    pedalchopper Member

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  8. xXNightRiderXx

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    The magneto on these little engines are not strong enough to have any kind of electrical system apart from ignition and maybe a weak headlight. Emphasis on maybe. I'm adding the 110a 12v alternator so I can have audio, lights, and charging ports. Possibly more.

    zpt
     
  9. KCvale

    KCvale Active Member

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    The BT80 is not an HT engine, it is a measured 70cc 2-stroke with an oil bath centrifugal clutch, 12V generator, electric start and pull start.

    I have mine in the build bay now to get that engine out and re-use the bike.


    Save
     
  10. xXNightRiderXx

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    It's not just the voltage. It's also the wattage and the amperage. Everything you have on that system must NOT exceed the wattage of the system, nor the amperage. Voltage is simply the rate of flow, amperage is the strength of that flow, wattage is how much work that flow can make. My audio system is a 60W system, my headlight is 35, my tail light is about 20. That right there is 115W out of possibly 200W put out by the alternator. The amplifier for the audio system is likely a 10A amp. My lights are no more than 2A each. The speakers another 5A each. My battery charger is probably a 30A. That's 56A allowing me to place a bit more on the bike.

    Those magnetos are probably only 10A 40W generators, so you can't put a whole lot on them. But don't take me at my word. You should measure the two. Particularly the watts, because that is the biggest deciding factor as to what you put on the system. All the bright headlights I found have not been lower than 20W, other than cheap, weak, throwaway lights.

    Hey KC, any chance I could get that broken down engine to tinker with? I've always wanted to work on an electric start two stroke. If I could make it last more than another 20 starts, I will give it back to you saying "It's fixed."

    What's making it not start anyways? Most of my no start issues with my 66cc were simply because of gaskets, carb, and slight electrical. I actually took apart my carb a couple times, and air blasted everything. Then it started and ran cleanly. Oh, and I think the reason my spark plug blew is because I went way too small with my jet. I did a .62 instead of a .66 from a .7. I thought I had a .66 though, but I found out after the fact that those engines come stock with a .7 jet. Hey, fun fact about those jets: You can clear them with a mechanical pencil. Or get a wax carving set and use the needle point tools and compressed air. That will work for smaller jets.
     
    #10 xXNightRiderXx, May 1, 2017
    Last edited: May 1, 2017
  11. gstrope

    gstrope Member

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    I went ahead and put on a front brake. the bike had forward pegs on the front fork. I repurposed the mounts for the pegs to make a front brake mount.
     

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  12. xXNightRiderXx

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    Looks pretty good. Caliper brakes are nice to have because they look clean. Same with cantilever and center pull brakes. The best brakes by far are V brakes. They don't look as clean, but the stopping power is almost limitless for a rim brake. You could use a v brake in the rear for pullin a 180° turn in two seconds. Fast enough to outwit a cop. You could also do very fast 90° turns just by locking your rear tire without throttle, making the 90, then hittin the throttle. This is best done in wet conditions however, as it will reduce the amount the ground wears your tire down.
     
  13. KCvale

    KCvale Active Member

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    You don't need to explain electricity to me, I am a CET with 30 years experience and still going with E-bikes.

    All the mag does is charge a 12V battery through a regulator so it can power the electric start, with a big enough battery you could power most anything as it's always charging.

    Sure, there is always a chance ;-}

    Really?
     
  14. xXNightRiderXx

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    Yes, really. You never said what was wrong with it.
     
  15. KCvale

    KCvale Active Member

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    I have said it dozens of times!
    I have my web site with a big topic about it, as does this site and others!

    You can't pedal start the engine, it has 2 ways to start, electric or pull start, both broke on the original kit, and both replacement parts broke soon after installation.

    I think we can forget about me giving you that engine for you to 'fix', you clearly have no clue what it even is or how it works.
     
  16. xXNightRiderXx

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    I know the engine is an electric/pull start 70cc two stroke engine, and it works by precompressing the fuel/air mixture to force it into the combustion chamber. The compression stroke then causes low pressure in the crank case, drawing fuel and air into the case. The power stroke then precompresses the mixture again, and the cycle repeats. However, because that precompression forces the mixture into the combustion chamber, a bit also gets pushed out of the exhaust port. This is where a tuned pipe pushes that mixture back into the cylinder by way of sonic waves. I know how two strokes work, regardless of whether they're automatic or manual. I had a crappy little china girl, ok? That thing had problems up the wazoo. I lapped my head, cleaned the carb, got a broken exhaust pipe right at the muffler, so I had to build one, I had clutch issues, I had chain and tensioner issues, I even had a blown spark plug. I did my research on two strokes. Just because I'm fairly new to this place doesn't mean I am an idiot when it comes to all engines. Trust me when I say I can get that engine starting and running without a hitch. I know what it is, I know how it works, what I don't know is the electrical system. That I will need help with. Thankfully, I have a multimeter, so I can measure the thing when its started. I can find a way to start it without the pull or electric starters.

    UPDATE: I looked, but I couldn't find a bt80 on your site. Could you give me the name of the thread?
     
    #16 xXNightRiderXx, May 3, 2017
    Last edited: May 3, 2017
  17. xseler

    xseler Well-Known Member

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  18. KCvale

    KCvale Active Member

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    You going to try to mod it like Don Grube did his electric start GT5A engines?

    [​IMG]

    That won't work either.

    The engine has an oil bath centrifugal clutch so like all 4-strokes you can't bump start it.

    Please prey tell how you can magically start this engine without using the pull or electric start?

    http://kcsbikes.com/topic.asp?TOPIC_ID=948
     
  19. beetleman217

    beetleman217 New Member

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    Nice build, gstrope. I have to ask though, will the Bullet Train engine fit on the OCC stingray if I leave the pedals and chain functional? What I'm basically asking is did you drop all those just because you wanted it to be a motorcycle, or because it wouldn't fit otherwise? After all there's both that bulge and the muffler on the right side (unlike the regular china girl motors) to interfere with the chain.
    Cheers
     
  20. gstrope

    gstrope Member

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    I didn't try it. The kit does come with a wide expanded crank though. I think it could be done. You might want to view some youtube about bullet train install
     

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