Run's Well,but Wondering.............................

Discussion in '2-Stroke Engines' started by geebt48cc, May 2, 2010.

  1. geebt48cc

    geebt48cc Member

    What Is The Greatest PERformance Modification For A Stock 49cc 2/Stroke Engine? .....skyhawk,400 Miles,25/1mix:d

    Ty/glen
     

  2. Pablo

    Pablo Motored Bikes Sponsor

    two words: expansion chamber
     
  3. Al.Fisherman

    Al.Fisherman Active Member

    I'm going to get a shift kit, actually all those that have ordered the roller bracket from me are buying it. I want to thank them all, but back to the subject....on a scale of 1(low) - 10, where would you place the expansion chamber and a shift kit, and why.

    Now as to what I'm looking at is not speed as my bike will go faster WOT then I can for any length of time. It's plenty fast enough to go on a bicycle made for less then 10 MPH. I'm looking at the fact that with a shift kit I can attain my normal speed of 10-15MPH at a lower RPM with the shift kit, thus extending the life of these engines. What say you Paul?
     
    Last edited: May 2, 2010
  4. Pablo

    Pablo Motored Bikes Sponsor

    I'm a bit strange, I don't actually consider the shift kit a "performance modification". The reasoning is this:

    a) it doesn't change performance so much as it's so completely different, I mean converting an AT to MT in car (which I have done) is less drastic. It's not a modification. It's a......I dunno...renewal, revolution, complete do over. That said it will get you from zero to 35 way faster than any bolt on sprocket bike, so for that reason it's a 10!

    b) Even with a shifter kit, you will still want the cool stuff like roller clutch, expansion chamber, higher compression, ports matched to mani's....etc...so for bolt on performance mod, there still is nothing better than an expansion chamber on a 2 stroke. 10.
     
  5. motorpsycho

    motorpsycho Active Member

    I have a 49 c.c. slant head on a 20" frame with 20" wheels.
    the biggest performance upgrade that i have made is by adding an expansion chamber and a high flow air filter.
    But, carb tuning is a huge thing with these engines. getting the carb just right is another key to performance.
    a better spark plug wire, boot and an ngk spark plug will also add a little power. another thing that a lot of people forget about is indexing the spark plug. you need to get indexing washers to do this, but basically you align the opening of the electrode on the spark plug directly in like with the path of the intake. this takes some trial and error and messing with the indexing washers but it will add a tiny bit of performace. is it really worth the effort? probably not to everyone, but i did it.
    I have also dropped from a 44 tooth sprocket to a 41, only because i am using the small 20" wheels. the 41 tooth gives my bike a little more top end, but the biggest improvement by going to the 41 tooth sprocket is the mid range.
    with the 44 tooth, the engine would reach it's peak torque way too soon (it would wind out too fast). now with the 41 tooth, it still has plenty of bottom end take off, but the midrange pull has greatly increased. the torque curve is not so ,uch a peak now, it;s more of a flat line and it pulls longer and harder.
    milling the stock head will raise the compression, or you could just buy a billit high compression head.
    also, yiur fuel/oil ratio will make a big difference in performance. i found that running 32:1 makes the most power for me....and i use synthetic 2 stroke oil and 87 octane regular gas.
     
  6. nvrgoingslow

    nvrgoingslow New Member

    it would probably have to be a supercharger with turbo
     
  7. G-Superior

    G-Superior Member

    What ???????????

    A two stroke with supercharger and turbo??????? never heard of one:ack2:
    IT would do 1MPG and the exhaust would be full of unburned fuel, it would fill up a swiming pool of fuel in 2 minutes!
    SUPERCHARGER + 2 STROKE = WASTE OF FUEL + MONEY , SUPERCHARGER + TURBO + 2 STROKE = WASTE OF TIME, MONEY AND FUEL
    G-Superior :D
     
  8. nvrgoingslow

    nvrgoingslow New Member

    G superior .................it was a JOKE...... as for the unburned fuel just throw a a fan and a extra spark plug back there 2 stroke+supercharger+turbo+sparkplug+fan = one fast ride with afterburner...........and it would be badass......top fuel dragsters get not even one mile to the gallon but there still cool and badass!!!!
     
  9. AussieSteve

    AussieSteve Active Member

    Don't forget the NOS
     
  10. motorpsycho

    motorpsycho Active Member

    actually, some firetrucks use 2 stroke diesel's with a supercharger and a turbo. the turbo blows into the supercharger.
    these engines are very efficient and make HUGE torque numbers.
     
  11. G-Superior

    G-Superior Member

    motorpsycho dont try to compare a high tech. 2 stroke diesel engine to a HT!:D
    and the superchargers and turbos on 2 stroke diesels only push air in and then when the piston is a few degres before tdc it injects diesel in so it dosent matter if a bit of air gets blow out of the exhaust port because there is no fuel in it
    BUT WHAT ARE WE TALKING ABOUT DIESEL ENGINES IF THE ORIGINAL QUESTION IN THE THREAD WAS What Is The Greatest PERformance Modification For A Stock 49cc 2/Stroke Engine?
    So lets help geebt48cc to make his engine a Bomb and stop talking about other things that will not do anything to a HT and will never be put on a HT!:rolleyes7:
    G-Superior:D
     
  12. AussieSteve

    AussieSteve Active Member

    No sense of humour, G-Superior?
    It started as a quite appropriate one-line joke.
    You were the one to make a big deal of it.
    Lighten up.
     
  13. G-Superior

    G-Superior Member

    I was actually being nice and i do have lots of sense of humour :D just want to be sure that geebt48cc gets some good ideas:eek:
    Dont even remember last time that i have been nasty to someone:grin5:
    and there is no point in fighting or arguing online, never ends and never gets anywhere:whistling:
    and like my dad says:
    there is no point in getting stressed because all you will get back is bad skin and more to worrie about :grin5: (it sounds funny when he says it!)
    G-Superior :D