best low end power

Discussion in 'Motorized Bicycle General Discussion' started by walander, Feb 24, 2011.

  1. walander

    walander New Member

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    Hey, I have been building for a bit now, some may have seen pics of my newest build I just posted on the cruiser forum. But I have always built cruisers and always used grubee gt5's. But now I think I want to build a mountain bike for trail riding. My question is, does a 4 stroke offer better low end power? I know nothing about 4 stroke motors. I was looking at the 49cc from deamon bikes. Aside from reliability and not mixing your oil, what benefits does a 4 stroke offer? Can I expect more power or speed from a 49cc 4stroker? also what does anyone think about fitting this thing to a bike? AUTO 125CC 4-STROKE ENGINE MOTOR ATV GO KART DIRT BIKE - eBay (item 150565213084 end time Feb-28-11 02:13:27 PST)
     
  2. meerkatt

    meerkatt New Member

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    The answer will always be generalizations, but... in general.... a 4 stroke will be heavier & generate less hp but more torque for a given capacity & rpm. So yes, low end can be better than 2 stroke. 4 stroke reliability is a myth, there are more moving parts so there is more that can go wrong. rings, pistons & cylinders do sometimes last longer as the rpm is often lower.
     
  3. professor

    professor New Member

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    Four strokes have much more low speed torque and less hp (as mentioned above) but for trail riding a geared down 2 stroke would be lighter.
    The engine in your link lacks a carb and would need a battery and wiring plus exhaust system. Suitable for an experienced fabricator/ mechanic.

    By the way- there is no way a 2 stroke will last as long without re-building, as a 4 stroke will last.
    The power strokes are double and the heat created is doubled.
    One plus with the smoker is they are very easy to re-fresh.
     
  4. meerkatt

    meerkatt New Member

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    this laydown type motor is also REALLY bulky and long, power to weight wise it is not a contender for what you want to do IMO. Run in a pitbike they are fine for little kids.
     
  5. matthurd

    matthurd New Member

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    the fact that the 4 stroke says it's top speed is 35 mph is laughable to be honest, it sucks up more fuel has nearly 2-3x the displacement and wont give you any more power then our little chinese 2 stroke kits?

    if their numbers are accurate thats a gigantic waste.
     
  6. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    There have been a few guys who showed up on our monthly So-Cal club rides with 4-stroke engines; (some bragging how fast they were.) :rolleyes:
    They have always ended up at the back of the pack once we got rollin'! ;)

    IMHO, if you want good low end power for trail riding?, a fully ported HT with a giant rear sprocket will make you very happy! (^)
     
    #6 Venice Motor Bikes, Feb 24, 2011
    Last edited: Feb 24, 2011

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