Recommendations for building a 4 stroke with a shift kit

Discussion in '4-Stroke Engines' started by mrbg, Jul 27, 2016.

  1. mrbg

    mrbg Member

    Hey I've been riding the 2 stroke Kit's for a few years,currently have two.Grubee and a old Nirve . I'm in the planning stages, I want to build a good quality bike with a shift kit.1st what's the best way to go for gears 5 speed cassette or a Sturmey Archer 3 spd hub ? 2nd motor and centrifugal cltch trans ?So far I've been told the DAX Trans isn't as good as the grubee . I like the Titan 4 stroke kit they have,also the Helios kit . I haven't looked at the shift kits yet . Any suggestions will be appreciated, thanks

  2. bakaneko

    bakaneko Active Member

    That Titan XC50R looks like a HuaSheng with a different sticker... Am I missing something?
  3. mrbg

    mrbg Member

    The ad says built in US ,it doesn't say made in the USA. Ad says 3.25 hp. steel cylinder,3 ring piston and the price is competitive
  4. bakaneko

    bakaneko Active Member

    Yeh, I'm just curious because the Harbor Freight 79cc produces 3.5HP and this 49cc produces 3.25HP. I am just curious as to how they made the 49cc produce 3.25HP as advertised.
  5. CrazyDan

    CrazyDan Active Member

    I've been confused with this as well, even a gxh50 ported and polished, lithium plug, jetted, better air filter and the best exhaust doesn't produce 3.25 hp. I've just assumed its an exaggeration to increase sales. I've seen the hs 142f advertised somewhere to have 10.2 kw, which roughly translates to 13.6 hp . Gross exaggeration to the point of false advertisement or pure ignorance. I can't see that big of an error being accidental, while the dax motor might have 2.25 hp and someone slipped and hit 3 instead of 2.
    Last edited: Jul 28, 2016
  6. Frankenstein

    Frankenstein Well-Known Member

    I've been researching this idea closely too, been examining the dimensions of my schwinn Stingray as my pet project for the winter, want to get the largest possible 4 stroke I can in it without cutting the frame or welding it, the only thing that may get toasted is the pedals, they might become just foot rests with a lever built into one side for the rear brake.

    So far the doodlebug db30 motor (a Honda gx100 clone) is looking like my best candidate. I can get a manual clutch (Yea I like em) that will be affixed to the output shaft, then some fancy jackshaft rigging and I'll have a nuvinci hub most likely in the back, or possibly an internal geared hub, have to say the nuvinci has been holding up to the relative hell I put it through, a good winter, being stored in freezing conditions (I had to break the bike free of an armor of ice, and 3 quarters buried in snow. Then used in that cold state without prewarming 3 miles to work since the roads were gridlocked with incapacitated vehicles of all sorts, including a jack knifed tractor-trailer) broke a couple spokes with it too, rain, sleet, ice, salt and grit, going from freezing Temps nearly directly into hot operating Temps, a very powerful 2 stroke pulling my 210lb hindquarters up some ridiculous Hills.

    Anyway, the hub in combo with a clutch of some kind with a 4 stroke should be a great way to get around. The doodlebug motor is a 97cc, which is much bigger than the very common 49ers, has more oomph than a 79 cc predator, but still small enough for my task, while also having enough punch to feel more like a 66 2 stroke, but with a better power band, and of course the many many advantages of a 4 stroke.

    It's just I never really dabbled with 4 stokes much, so I'm intimidated by the idea that if something goes wrong I will have no real idea what to do, and I don't know anyone except a guy in the next town over who knows anything about 4 strokes (he buys, repairs, and sells riding mowers)

    Also going to be forced to use a different chain type for the clutch, it's a #35 sprocket, so I'll need yet another chain breaker, then I'll use a #35 sprocket on a 5/8th keyshaft, then the other side will be a normal 1/4th pitch chain, as thick as I can get for the thickest sprocket I can get for the hub, this time I want to go with some serious durability.