shifter kit/jack shaft/boost bottle

Discussion in '2-Stroke Engines' started by adrian101, Apr 23, 2011.

  1. adrian101

    adrian101 Member

    I have some questions regarding shifter kits.

    Do they increase the life of the engine?
    Do they increase the speed of the bike as it runs off the bicycle gears?

    Is 300aud to much to pay for one?

    do the boost bottles really work on motorized bikes or not?

  2. TucsonDIrect

    TucsonDIrect Member

    Boost bottle and expansion Chamber YES! Look up how a two stroke works and you will know right off the bat

    Shift kit... idk dont have one
  3. motorpsycho

    motorpsycho Active Member

    a shift kit will not prolong the life of the engine.
    It will increase the top speed opf the bole tho since you can have more than one gear to go through (like a transmission).
    the bonus is that it gives you the best of both worlds...low gearing for good take off, and high gearing for top speed. It will allow you to cruise at 25-30 mph in a higher gear, which will make the engine run at lower rpms. That would be less strain on the engine, and higher mpg.
    I personally would not buy a shift kit simply because of the cost. I can build 2 single speed motorized bikes for the cost of one shift kit.

    boostbottles...some people say they work and some say they don't. a boost bottle can work as long as the engine is set up to make it work (this requires internal modifications to the ports). i have read about people just bolting a boost bottle on and then saying that they notice a difference in idle, the engine is easier to start, and it gave a little more performance. I bolted one on and the only difference i saw was that my wallet was $20.00 lighter. so, boost bottles are debateable.

    an expansion chamber will definitly give you more power as will a better high flowing air filter.
    also consider going to an ngk spark plug, and an automotive style spark plug wire with a rubber boot on the end.
  4. goodtime65

    goodtime65 Member

    My motor was always running pretty good but I could never reach full throttle because the engine would start to cycle. I instaled a boost bottle on this engine and now i can ride it wide open with no cycling of the engine. Its awesome. I than instaled a velocity stack from JNMOTORS and now it just flies, It takes a bit for everything to perform but I get my revs up it just takes off. Im running a 38 tooth sprocket and my buddy uses a 44 and I can out power him on any hill and leave him behind. Well worth the bucks
  5. Pablo

    Pablo Motored Bikes Sponsor

    1) It can if you select the proper gear ratio. The thing is, you will end up riding he bike much more because it will be so fun.
    2) It will definitely increase your acceleration from a standing start.
    3) I think even with shipping the $199 HD SBP kit will be under $300. ~250.
    4) Boost bottles don't work for me. Nothing beats an expansion chamber for bolt on engine power.
  6. adrian101

    adrian101 Member

    Thank you all for the help in answering my questions. Does anyone know if SBP has the black expansion chamber in stock. It says it doesn't on their website :(
  7. Pablo

    Pablo Motored Bikes Sponsor

    A couple people said this in the last several days. I can assure you we are fully stocked. I'm guessing - Maybe you need to just fresh your browser, because it hasn't said sold out since this time last week. Thanks!
  8. adrian101

    adrian101 Member

    Do you ship to Australia? would you have an guesstimate time of devilry? lol

    do you think it will fit nicely on a bicycle like this below:

  9. Pablo

    Pablo Motored Bikes Sponsor

  10. gothicguy64

    gothicguy64 Member

    let me answer all ur q but boost

    yes sbp ship here too syd ..takes less than 2 weeks
    yes a expansion is the best exhaust other than a power pipe
    yes i have a 48cc rse motor its a hp2.5
    bike has 7 gears (14-28) but u want a 8spd 11-32
    im in villawood

  11. damo99

    damo99 New Member

    shift kit and expansion chamber are the best mods you can do to your bike
    i live in melbourne(australia ) and got my shift kit($240 to my door with a air fillter) and expansion chamber from sick bike parts in one week (ordered monday ,arrived next monday) i also got a air fillter .
    my bikes gone from just getting 25klms to a tourqey beast that can now do 50klms in 6th gear .+ more to go (not run in yet)
    i did notice a huge difrence by changing back wheels with diffrent ratio cassettes on them ,just got to find the right one
    hope this helps
  12. gothicguy64

    gothicguy64 Member

    depending on ur gears ull want a 11-32 7 or 8 spd best place i got mine from was anaconda sports or
    im in syd

  13. spad4me

    spad4me Member

    Just my two cents.
    I would not even bother to build a motorized bicycle without some sort of shift kit.
    For me boost bottles do not work at all.
    A two stroke with an expansion chamber is the way to go for power.

    Basicly a cheap supercharger