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Thread: About a GP125 engine

  1. #1
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    14th November 2009 - 11:52
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    About a GP125 engine

    i have recently brought a gp125 bucket. i want to change to gearbox oil and i was wondering if anyone knew how much to use and what grade to use??

    Cheers

  2. #2
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    5th June 2005 - 18:35
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    800ml at oil change or 850ml when dry. The manual says to use 20/40.
    Life is a lesson-if I bother to listen

  3. #3
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    14th November 2009 - 11:52
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    Thanks bud. Ill change it and see if it runs any better. Another thing what does it mean if when i go to take off and it just wants to die on me?? It revs fine when clutch is in or in neutral but as soon as i let the clutch out it wants to die! any advice anyone??

  4. #4
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    18th May 2007 - 20:23
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    Quote Originally Posted by adam-stevens View Post
    i have recently brought a gp125 bucket......Cheers
    GP125's are the go..... I would love to see a photo........

  5. #5
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    16th November 2006 - 23:46
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    I gather you bought Coyote's bucket. What was sketchy's bucket before then (and i've seen it do 11 o'clock wheelies so its not that slow!) Good stuff man!

    Regarding the dieing when trying to load it up. Someone will come along soon with the proper answers. But to me it sounds like a clogged Jet's and general crap in the carb.
    What is very possible knowing how long that's GP has been sitting around. Give it a clean out and she should be running sweet!

    I know the bike needs a little bit of work, so make sure its tidy and fully nylon when you come up to Kaitoke for the first time. Gonna come up and watch this weekend?
    www.bucketracing.co.nz for more details about bike prep under the resources tab.

    Good Stuff! =).

  6. #6
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    25th March 2004 - 17:22
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    As above. The mixture is too weak. Chances are the pilot jet is clogged. Take carb apart (simplicity itself) & take out the small jet down the hole & blow through it until you can see daylight. Don't poke wire through it, you'll ovalise it. Once that is clear try again. Adjust the mixture screw in if still dies under load. If full-in you need a bigger pilot jet.
    Don't you look at my accountant.
    He's the only one I've got.

  7. #7
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    16th November 2006 - 23:46
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    Quote Originally Posted by F5 Dave View Post
    As above. The mixture is too weak. Chances are the pilot jet is clogged. Take carb apart (simplicity itself) & take out the small jet down the hole & blow through it until you can see daylight. Don't poke wire through it, you'll ovalise it. Once that is clear try again. Adjust the mixture screw in if still dies under load. If full-in you need a bigger pilot jet.
    While we are on this subject. I have always kinda of known what jet effect what part of Rev Range, but never confirmed it.

    Pilot Jet = for the idle?
    Main Jet = for the top end?
    Needle = Low/Mid Range?

  8. #8
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    25th March 2004 - 17:22
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    Ahh, this is where we get in trouble. Depends what type of carb. Mostly on small bikes, 2 strokes almost exclusively you have straight pull carbs (unlike CVs used esp on 4 cl 4 strokes).

    So the jets correspond to the throttle position. That takes a while to sink in because the bike may respond seemingly to the revs it is doing, but you must think about the throttle position. So Pilot jet & mixture screw is for throttle closed & opening from closed. Then as it opens you are on needle, & near full on- the main. Of course there is some blending, but changing the mixture screw isn't going to do much for a too small of a mainjet for example.

    As a rough guide the mixture screw position should tell you which way to adjust it for richer. If like most 2 strokes the screw is on the airbox side of the slide, turning it 'in' will be richer & out will be leaner. If you run out of reasonable movement go the next size smaller or bigger as required.

    If the position of the screw is on the intake side; the inverse as it is bleeding in extra gas rather than air.
    Don't you look at my accountant.
    He's the only one I've got.

  9. #9
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    4th February 2005 - 07:32
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    I seem to recall.

    closed to 1/8 th air screw and slide cutaway
    1/8 to 1/4 pilot jet
    1/4 to 1/2 needle (Could be 1/4 to 3/4 memory fails)
    1/2 to open main

    As said there is some crossover from one to the other but this should be where each component has it's major effect.

  10. #10
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    14th November 2009 - 11:52
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    Thanks everyone!! i just want to get out on the track and race haha!!! all i need to get now is some leathers and a back protector and to tidy up my bike and nylon it!!

  11. #11
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    4th November 2003 - 00:41
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    This might be of some use:
    Click image for larger version. 

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ID:	204031Click image for larger version. 

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ID:	204047
    The Unknown Rider

  12. #12
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    14th November 2009 - 11:52
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    cheers mate

  13. #13
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    31st July 2005 - 11:15
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  14. #14
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    30th September 2008 - 09:31
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    Quote Originally Posted by TZ350 View Post
    GP125's are the go..... I would love to see a photo........
    Me too......................we just love those GP's

  15. #15
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    14th November 2009 - 11:52
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    i have taken the carb apart and cleaned it all throughly and it still just wants to die when i let the clutch out. im thinking that it might be the clutch?? Where might the clutch be?? i cant really think what else it might be!!!!

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