Zip 50 problems help please!!!

Discussion in 'Scooter Tuning' started by glenbob91, Jan 3, 2014.

  1. glenbob91

    glenbob91 New Member

    Messages:
    15
    Hi all im having trouble with my zip 50 basically its got a tt piipe and recently i bought a 19mm tnt race carb, i then got the recommended 98 jet and mushroom air filter, iv fitted it all to the bike and i can get it to run but not right.... It doesn't like to pull of and when it gets going itdoesnt want to stop lol it just keeps revving which although exciting its pretty dangerous lol can anybody help please
     
  2. turbovetto

    turbovetto Well-Known Member

    Messages:
    1,561
    Rides:
    tweaked ovetto
    Hi
    check your plug colour - sounds like you're poor. Put a 110 in there and work down 'till it runs.
    If it still won't go at the start, and you just put a sponge filter on there - you're too poor at the start. Get the principle jet sorted first. Then rich up the start with the mixture/air screw.
    Then check the carb for a sticky slider & check your throttle cable.
     
  3. glenbob91

    glenbob91 New Member

    Messages:
    15
    Well basically i got that problem sorted and now it pulls very well but bogs at high speed now lol i cant understand why
     
  4. turbovetto

    turbovetto Well-Known Member

    Messages:
    1,561
    Rides:
    tweaked ovetto
    If you've got a nice brick-brown plug colour then you're too heavy on the rollers. If you're plug is grey - you're too poor on the principle jet. I would start with the plug & the main jet.
    Good luck
     
  5. glenbob91

    glenbob91 New Member

    Messages:
    15
    Plug color seems fine main jet is a 98 isit to small?
     
  6. turbovetto

    turbovetto Well-Known Member

    Messages:
    1,561
    Rides:
    tweaked ovetto
    Dunno. Probably. Try 115 and then work down. What you're trying to do is make it too rich and then work down. This is how you avoid damage. I'm running a 28 mm carb with a modified airbox - it has a 20 mm intake hole. 120 is too rich. 118 is a bit better.115 is about right.
    If you're running a sponge filter (which is about the same as having the carb wide open & naked) then I suspect that 98 might be a bit small.
    If I put the stage 6 sponge on my 28 mm carb - I know from experience that the main jet is anywhere between 142 and 130 depending on the weather & the kit/exhaust. You're a long way from that - and your carb is only 9 mm smaller than mine. Engine capacity has surprisingly little to do with it. I once took off a 70 kit, put on a 50 without changing the carb/filter and didn't need to change the main jet........
    So upjet - make it so it coughs soot like a bastard - and then go down by values of 5 at a time. A box of jets it cheaper than a new piston/cylinder.

    Good luck
     
  7. glenbob91

    glenbob91 New Member

    Messages:
    15
    Ok thanks alot
     

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