250 Thumpstar won't idle without choke on

Discussion in 'Carby & Tuning' started by anthony.sansom, Mar 20, 2011.

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  1. Mar 20, 2011 #1

    anthony.sansom

    anthony.sansom

    anthony.sansom

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    Hi guys and gals

    I have a thumpstar with a 250cc zongshen engine,

    bike starts ok but wont run without choke on, I took the carby to a motorcycle repair center and they cleaned the jets for me but still wont run unless choke on,

    It some times runs without choke but soon as you rev it it just dies,

    I took out the 4 screws on carby so it was in two peices and it looks clean inside, is there other parts of carby that should be cleaned aswell????

    I replced fuel line aswell, still no go???
     
  2. Mar 20, 2011 #2

    Lethalleigh29

    Lethalleigh29

    Lethalleigh29

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    check your valve clearances sounds exactly like my atomik raider same symptoms and my valve clearances were out now it runs like a dream
     
  3. Mar 20, 2011 #3

    Lethalleigh29

    Lethalleigh29

    Lethalleigh29

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  4. Mar 20, 2011 #4

    timmonds

    timmonds

    timmonds

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    yeah, id think it might be running a little lean. might be wrong, but probly be a good place to start as well as valve clearances. also how new is the bike?
     
  5. Mar 21, 2011 #5

    anthony.sansom

    anthony.sansom

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    would not be any older then 5 years,

    Thats a great guide i will have a crack,

    I dont have the caps on top of my engine, would they be under the rocker cover

    Maybe its a push rod engine and not OHC, Does anyone know how to tell the diffirence?????
    I did read that the zongshen 250cc engine has OHC and push rod.

    How do u adjust the fuel mixtures if it is eunning lean???
     
  6. Mar 21, 2011 #6

    Lethalleigh29

    Lethalleigh29

    Lethalleigh29

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    my 250cc is OHC so it was ok.. that has me scratching my chin.. as for your fuel mixtures theres a good carby guide it the tutorial section that has pictures of all carbys and shows were the needles are..
     

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