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  1. #1
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    throttle responce flat spot

    can anyone explane why when on tick over i put foot to the floor and theres a flat spot and most time it cuts out ? stock jets and 2nd stage drilled to 1.2mm
    is it just a carb thing or can i correct this ?

  2. #2
    Non-member Andrew Cooke's Avatar
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    Re: throttle responce flat spot

    how's your pump jet set?

  3. #3
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    Re: throttle responce flat spot

    wheres that ? probs still standerd as ive not played with it

  4. #4
    Non-member Andrew Cooke's Avatar
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    Re: throttle responce flat spot

    have you read this?

    https://www.rtoc.org/boards/showthread.php?t=27381

    first thing is to remove the elbow, and look down into the carb. When you open the throttle (engine off) you should get a nice quirt of fuel out of the tube (you might need a torch). If you don't, or it's dribbling out somewhere else you've found your problem.

  5. #5
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    Re: throttle responce flat spot

    yes i done this the other day and it wasent squirting out very well just a little dribble
    does this mean i need to do a full overall or can i fix the prob on its own ?

  6. #6
    Non-member Brigsy's Avatar
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    Re: throttle responce flat spot

    Pull the jet out of the carb body and clean it thoroughly with carb cleaner.

  7. #7
    Non-member Andrew Cooke's Avatar
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    Re: throttle responce flat spot

    also check if the pump arm is seized

  8. #8
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    Re: throttle responce flat spot

    ok i will have a look 2mo thanks

  9. #9
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    Re: throttle responce flat spot

    pump arm was not moving as it should found the prob many thanks

  10. #10
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    Re: throttle responce flat spot

    well thought id solved the prob but still the same the took the diaphram out looks find it was sticking abit so free it off but still getting flat spot ?

  11. #11
    Moderator, Committee Trevhib's Avatar
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    Re: throttle responce flat spot

    Andy wrote: "first thing is to remove the elbow, and look down into the carb. When you open the throttle (engine off) you should get a nice quirt of fuel out of the tube"

    Did you do this?

  12. #12
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    Re: throttle responce flat spot

    yes thats seems ok now

  13. #13
    Moderator, Committee Trevhib's Avatar
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    Re: throttle responce flat spot

    air leak around the carb base or similar?

  14. #14
    Non-member Markey Mark (BD)'s Avatar
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    Re: throttle responce flat spot

    Sounds like the pump jet arm could do with adjusting

  15. #15
    Moderator, Committee Trevhib's Avatar
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    Re: throttle responce flat spot

    Looks like it was seized originally, then freed off, so perhaps now needs adjustment like you say Mark.

  16. #16
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    Re: throttle responce flat spot

    how do i ajust pump jet arm

  17. #17
    Moderator, Committee Trevhib's Avatar
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    Re: throttle responce flat spot

    Quote Originally Posted by Andrew Cooke View Post
    Kev, it's in here.

  18. #18
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    Re: throttle responce flat spot

    its says in the diagram not to touch / ajust screw on accelerator arm ?

  19. #19
    Moderator, Committee Trevhib's Avatar
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    Re: throttle responce flat spot

    Well that would depend on whether yours is in the position it was when it came out of the factory. If it isn't it will probably need adjusting.

    I'm not sure where you're looking where it says not to touch it but the diagram in the last post describes exactly what to do to set it correctly, figure 13.9. Assuming I've understood it correctly.

  20. #20
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    Re: throttle responce flat spot

    trev you lost me now mate lol

  21. #21
    Moderator, Committee Trevhib's Avatar
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    Re: throttle responce flat spot

    Well, within the information in the link provided there is a diagram-supported section called 'Accelerator Pump Jet Adjustment' which goes on to describe how to set the 'Accelerator Pump travel.'


  22. #22
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    Re: throttle responce flat spot

    arhhh i got what you mean now not in thread in last post lol something about a drill bit using to ajust ? hows this done it dont really explane that much ?
    Last edited by KEV 5 GT; 06-12-2013 at 22:28.

  23. #23
    Moderator, Committee Trevhib's Avatar
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    Re: throttle responce flat spot

    Quote Originally Posted by KEV 5 GT View Post
    arhhh i got what you mean now not in the thread, in the last post lol
    In my previous post I actually wrote, "the diagram in the last post describes exactly what to do."

    If you've seen the diagrams and description (which I think is pretty comprehensive), but still don't know what to do, then I can help you no further mate.

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