47cc cag mtb first build

Discussion in 'Introduce Yourself' started by bhaydonsuperpocket, Jan 26, 2012.

  1. bhaydonsuperpocket

    bhaydonsuperpocket New Member

    not 2 bad improving every time i play around i need more hp any help out there

    Attached Files:

  2. 5-7HEAVEN

    5-7HEAVEN Active Member

    Welcome to the club, bhaydon!

    You've picked an excellent combination as your first build, and a center-mounted engine to begin with! Props!

    What's your total gear ratio? Are you using a pocket bike gear box? The 5:1 box? Are you using a shift kit? What are your rear cassette gears?

    I'm also running a center-mounted engine combination. My final gear ratio in first gear is 46.36:1. This allows the bike to run up steep hills and ramps like a dirt bike. My final 8th gear is 15:1, but I like cruising in 7th gear, which is 17.72:1.

    Your biggest performance improvement will be low gear ratios. Geared correctly, your bike will try to buck you off, like a wild stallion!:devilish:
  3. bhaydonsuperpocket

    bhaydonsuperpocket New Member

    ive got a custom made 4 to1 belt cvt then a 14t bmx freewheel as drive to crank with a 44t crank and a 32t sprocket bolted to the 44t crank wheel and from 32t crank to rear wheel 52t sprocket had a 48t rear wheel but was slugish off the marke and wound out around 20 klm to about 45klm ruffly ok so changed rear to 52t and alot better off mark but lost a little top end so now ive modifiyed 39cc blata ajustable clutch to fit 47cc cag motor and been playn with ajustment and its heaps better off mark so may go back to 48t rear ive ported motor myself and ligthend flywheel changed spark plug lead custom blata exaust fitted made a double set ove reeds and just fited a walbro 15mm carby ajustable low and high ive found with the walbro that top end ant much diff but low and mid power is heaps better than standerd carby idels smoother now ive got to throw cash at it to be better motor mods and 8 speed internal hub so dont have to rev hard to cruize at about 50 60 klm and the ratio from turns ove crank to rear wheel is 9 to 1if u have any ideas please let me know
  4. 5-7HEAVEN

    5-7HEAVEN Active Member


    Unsure what your variable CVT ratio is, but at 4:1, your intermediate gear ratio is 12.57:1.

    With 32t/52t combo, final gear ratio is 20.43:1.

    With 32t/48t combo, final gear ratio is 18.86:1.

    With 32t/50t combo, final gear ratio would be 19.64:1.

    What is your variable CVT ratio?
  5. 5-7HEAVEN

    5-7HEAVEN Active Member

    Do you have an expansion pipe? If not, a pipe will add more power and higher rpms.
  6. bhaydonsuperpocket

    bhaydonsuperpocket New Member

    cvt is 4to1 and pipe have mta4 39cc pipe custom to fit bikewas thinkn ove usen 3 speed hub between cvt drive sprocket and crank or from crank to 3 speed hub and hub to rear wheel sprocket just depends on room and the power prob just got polini rep 50cc watercooled motor so maybe strip down and reconfiger cvt motor mount around 3 speed hub jack shaft