Which scooter powerplant for a project?

Discussion in 'Battle Scooters' started by Chillis, Apr 21, 2012.

  1. Chillis

    Chillis Land Barge Pilot

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    I got hooked on scooters after getting my first one just shy of a year ago but I want to make something that isn't available. A scooter engined all purpose cycle with recumbent seating position. Think a tubular version of those hyper-miler scooters that get 150+ mpg.

    The requirements for the engine:

    Cruise at 60 to 65mph

    Low maintenance(3,000 mile oil change intervals, valve adjustments twice as long)

    Can be carbed or FI.

    Has a 12" or bigger rear wheel that could handle 5" of travel, possibly more depending on the shock length.

    Engine can't have any adverse affects from being at more of an angle to the ground than normal(problems with oil pick up or transmission gears not being lubed by oil bath.

    Basically able to handle some light off road work.

    Thoughts?
    #1
  2. HandKPhil

    HandKPhil Been here awhile

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    I've been thinking about the same thing. Probably the best choice would be the drivetrain out of a new BV350, or a new Downtown 300, because they're the most advanced engines out there today as far as specific power output, efficiency, etc. Downside to these two choices are the cost, and the fact that you'd have to sacrifice one of two awesome new scooters to get your donor drivetrain.

    Next best choice might be a Burgman 400 or Majesty 400 drivetrain. These scooters are relatively cheap, and they're everywhere. These drivetrains are used to pulling around 700-plus pounds of man and machine, and their suspensions and brakes are also up to the task.

    Another reason favoring the Majesty 400 is that I happen to have one in my garage.:lol3
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  3. MODNROD

    MODNROD Decisions, decisions

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    If I was starting from scratch, and only needed cruise speeds below 70mph, I would factor in the strong aero advantage offered by building from scratch, and combined with exceptional light weight - if at all possible - would be looking at something around 125cc. The Yamaha BW motor is pretty efficient, and has an enormous aftermarket support, just in case you need to go bigger than you expect later, or need to tune-in the CVT stuff to suit the new ride.
    These things get great economy, and will happily do close to those speeds almost standard, so by the time you've got the lightweight and aero advantage it will do it real easy.

    To give an idea of aero effects, the Moto Guzzi 350cc IOM racers with their cool "dustbin" fairings had a top speed over 150MPH in the mid-50's. When the fairing design was banned, they could barely manage hi-120'sMPH........
    #3
  4. alicethomas

    alicethomas Been here awhile

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  5. TheReaper!

    TheReaper! Been here awhile

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  6. HandKPhil

    HandKPhil Been here awhile

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    I'm thinking about embarking on a three-wheeled Micro Car project, and I like the fact that the Majesty already has a beefy, die-cast central "spine" to build around. Try Googling "Naked Yamaha Majesty" to see some pictures. In regards to the O.P.'s needs I know that the highest point on the aluminum frame (near the seat position) is pretty low on a Majesty - perfect for a "feel forward" project.
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  7. Chillis

    Chillis Land Barge Pilot

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    Very good point on aerodynamics as well as the Yamaha 125 engine.

    This idea is tube frame, minimal bodywork, and able to play in the dirt.

    Bodywork will be minimal and still not even sure if passenger accommodations will be provided but they could double as storage space.
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  8. creighta

    creighta Been here awhile

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    I vote chinese for something like this, parts are cheap and you can find full bikes cheap too.

    On the other hand, there was a guy a few years ago on the helix forum that put a 500cc rotax sled engine in a stripped down helix.....BAD ASS.
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  9. Chillis

    Chillis Land Barge Pilot

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    Would you be willing to take a Chinese engined bike to the middle of nowhere?

    Are you talking GY6?
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  10. btcn

    btcn Long timer

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    Sounds cool! Please post up when you start building it!

    I can't really know about the oil lubercations and angles on these engines.

    I do agree on the aerodynamics though. If youse got real good aero, then you can gear the engine much taller [machine finial drive gears that's taller], and get much higher cruise speeds with low RPMs. Just don't overdo it on a smaller engine.

    As for maintainence. Most engines can do well over 2-3K with a good synthetic oil, even if recommended at less. Valve adjustments? I never did one for years on my Elite. Runs fine but I's gonna do it now.

    As for offroad. I take my old 86 Elite 150 off road all the time. And I don't exactly baby it! No flying 10 feet up in the air off jumps MX style, but I have some fun in the mud!

    Eventually I'm fixin to put some sort of skid plate under it though to protect the coolant hoses and such. But its not necessary unless you do it a lot.
    #10
  11. creighta

    creighta Been here awhile

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    yes I was thinking gy6. The Linhai 250s are also pretty reliable powerplants. I knowseveral people that trust gy6 150s or even Honda 250 clone engines out through Kentucky on gocarts without worry. Our local Hammerhead dealer even sent a 250 up pikes peak last summer, so the engines can handle a beating off road and the reliability issues of being chinese can be overcome by the performance rebuild work.
    #11
  12. vortexau

    vortexau Outside the Pod-bay

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    Except for that above- airflow efficient shells usually make riding off-road a problem.

    [​IMG]

    [​IMG]

    Honda aerodynamic scooter conversion results in 214 mpg


    [​IMG]
    One of the early test studies.
    #12
  13. TheReaper!

    TheReaper! Been here awhile

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  14. vortexau

    vortexau Outside the Pod-bay

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    Allert Jacobs is gunning for even more impressive results.

    I recall being happy with the 139mpg (Imperial) that was possible with a ordinary Honda C65 stepthrough back in the sixties. The 65cc motor was the FIRST OHC powerplant that Honda put into a Supercub.

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

    I seem to recollect that the auto maker Daihatsu selecting 993cc in the Three-cylinder configuration for reasons of efficiency way back in their post-WWII history - of particular in the Charade. It was something along the lines of 330cc being an optimum volume for each cylinder's peak efficiency.



    Coming soon: Three-cylinder engines

    Matt Campbell

    <cite>March 12, 2011</cite>


    Straight-three engine

    From Wikipedia

    From that idea, I derive a single cylinder of 300cc - 350cc as being a good compromise for optimum fuel efficiency with top road speeds in no way being hampered. That 125cc of Jacobs (of course) remains great at lower top speeds.

    Interesting, that my Burgman Exec employs two cylinders of 319cc each -- not so great for fuel economy, but it powers off from the line something wicked!
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  15. Chillis

    Chillis Land Barge Pilot

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    It's really tough researching what would work best for this application.

    Honda Helix(parts availability and can be had cheap)
    Kymco engines(125 to 200cc)-again, cheap and reliable
    GY6-cheap and able to be reliable, plenty of aftermarket.
    Yamaha Vino 125-Can find bikes cheap and parts still available.

    If the engine has a mount on the bottom it will be more difficult to have ground clearance. A horizontal engine will allow a lower profile frame design.

    Not sure about air versus water cooled. Obviously the air cooled will be simpler with the lack of plumbing.
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  16. vortexau

    vortexau Outside the Pod-bay

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    If a 'special' is enclosed in a streamlined shell for efficiency, then keeping an air-cooled motor from frying is going to be difficult. An advantage of the Liquid-cooled powerplant is that the radiator can be positioned at the optimum location -- and just connected up to the engine coolant stubs by hose cut to custom lengths.

    Experimental multi-cylinder liquid-cooled Harley Davidson prototypes built back in the sixties used an under-seat radiator.
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  17. Chillis

    Chillis Land Barge Pilot

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    The engine will definitely be exposed to the outside world. Most scooter designs conceal the head of the engine behind the riders feet. My plan is for the bottom frame to be at the top of the engine line.

    This idea is going to be tubular construction first. Then a body panel or two later for wind management.
    #17
  18. knucklehead90

    knucklehead90 Been here awhile

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    Never heard about those but have read about the Nova project a few times.

    http://www.bikerenews.com/AntiqueBikes/CodeNameNova.htm
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  19. vortexau

    vortexau Outside the Pod-bay

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    That series was the one/s to which I was making reference.

    from
    Nova The V-4 Harley you never saw!
    #19
  20. knucklehead90

    knucklehead90 Been here awhile

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    The Nova Project was in development in the mid-late 70's. I thought you might have been referring to something I hadn't heard about since you mentioned it was something in the 60's the HD was developing.

    I remember reading an article back in the early 80's about the Evolution motor - the article mentioned a multi-cylinder project that 'might' get on the market 'sometime'. I think it was Cycle World since I had a subscription to that mag at the time. Never heard any more about that. When the V-Rod rumors first came out I thought it might be a 4 cylinder motor and thought about that article.

    The latest rumor is that HD is going to place water cooling into a few of their larger touring models. The radiators (twin ones) would be on the crash bars (one to a side) and be quite small. Since the water jackets will only be in the heads the cylinders will be real cooling fins - not fake like we see on many water cooled cruisers trying to emulate the HD look.
    #20