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  1. #1

    New engine choice for a Rupp Roadster2

    I am looking to replace my original existing engine on my Rupp Roadster2 (early 70's model) with a new Tecumseh 4HP engine. I am looking for a simple bolt-in with no modifications. It seems that an easy replacement motor is the H40, but there seems to be many types of H40's out there. I've seen H40-55816, H40-55820, etc. Which motor works the best as far as throttle linkage hookups? Which internet company has the best price?

    Thanks in advance!

  2. #2

    Thumbs up new engine choice

    I think the motor your looking for is the hs40. Different from the h40. the hs is a smaller block. You would need a slant type intake pipe and the throttle linkage. A hs50 would work also, they're 5hp. hope this helped. Thanks, John

  3. #3
    Current production Tecumseh engine will be the hm40. It has minibike throttle linkage already installed. The new engines do not have mixture adjustments on the carbs and can make for engine being tempermental. The correct "early" model carbs will fit the new engines. The new engines do NOT have lighting coils. I have a dependable kit to install the lighting coils easily. I also have the carbs and engines are to be here late next week.

  4. #4
    x-90 rider's Avatar
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    Brandt,

    Do you need to install a spacer for the primary clutch. Is the output end of the crankshaft shorter on the new engines?

  5. #5
    Thanks for the info guys! I'll be looking into a new Tecumseh for my Roadster2.

  6. #6
    Senior Member I90Roadking's Avatar
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    Tecumseh

    Hi Brandt
    I have been looking into replacement motors for Arctic Cats. Other than no lighting coil, is the H40-55816 a bad move? The motors that you will be getting in, will they take a Comet Series 20 driver? Will you be placing on your web page?
    Thanks
    I90

  7. #7

    New Tec engines

    Quote Originally Posted by x-90 rider View Post
    Brandt,

    Do you need to install a spacer for the primary clutch. Is the output end of the crankshaft shorter on the new engines?

    The Rupp bushing is made of tool steel. No spacers needed when replacing an orginal Rupp engine with a new engine with shorter crank. All you need is a longer bolt and your set go go!

  8. #8
    all the late model Tec h40 engines are good choices. You may eventually need to put an early carb on it, so carb can be tuned properly for your elevation and weather conditions. The sealed carbs used now aren't a fault of Tecumseh, its the government and their clean air standards.

    The newer Tec engine will accept a Comet 20, 30 or TC88 driver

  9. #9
    Senior Member I90Roadking's Avatar
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    Thanks Brandt, appretiate the feedback.

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