Yes, another jetting question. ;o)

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bstewart8141
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Yes, another jetting question. ;o)

Post by bstewart8141 »

I recently convinced my girlfriend to get on the 2-stroke train and sale her CRF230f. So far she is loving her 2003 KDX200 but it was so hard to start when the bike was at operating temperature. I cleaned the card and replaced the 45 pilot with a 42 and it resolved the starting issue but ended up creating another. Last nigh after adjusting the idle screw "2 turns out" i noticed that the mid-range was very lazy till it got on the pipe and a small amount of gas was coming out of the carb whene cracking the throttle in the garage. Do I need to adjust the float? never had problems before and would a smaller pilot jet hurt the mid-range performance? Thanks for you time.


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-Brett Stewart
St. Louis MO
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KDXohio
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Re: Yes, another jetting question. ;o)

Post by KDXohio »

Float height would cause the gas overflow and having a high fuel level will impact the mid range
1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
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Julien D
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Re: Yes, another jetting question. ;o)

Post by Julien D »

What made you decide on 2 turns out? You should adjust the air screw for best off idle throttle response.
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bstewart8141
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Re: Yes, another jetting question. ;o)

Post by bstewart8141 »

Well every forum I read says to rev the engine a bit and slowly back the air screw out till it is at its hightest RPM which I don't understand because why would you want a bike reving like crazy just sitting there, maybe you could enlighten me on that. Every bike I have owned never reved high at idle and ran fine. 2 turns out it didn't sound like it was taking off and it was running decent. I also have noticed that when i crack the throttle or slow down the idle hangs ;-(.
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KDXohio
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Re: Yes, another jetting question. ;o)

Post by KDXohio »

You want to raise the idle with the idle speed screw then adjust the air screw
1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
bstewart8141
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Re: Yes, another jetting question. ;o)

Post by bstewart8141 »

KDXohio, I think I know where I went wrong. You the MAN!!!!! :drinkers:
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KDXohio
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Re: Yes, another jetting question. ;o)

Post by KDXohio »

1990 KDX200 FMF Fatty, Answer VFC silencer, VForce 3 Cage, Wiseco Piston, KX125-J series KYB USD fork conversion, Race tech goldvalves, J series front brake assembly, air-box snorkel removed, Acerbis Headlight, KX450F Front fender, Pro Taper RM bend bars, ASV front Brake lever, MSR Clutch perch and lever, RB Head mod, 36mm PWK carb, Trail Tech Kickstand.
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Julien D
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Re: Yes, another jetting question. ;o)

Post by Julien D »

bstewart8141 wrote:Well every forum I read says to rev the engine a bit and slowly back the air screw out till it is at its hightest RPM which I don't understand because why would you want a bike reving like crazy just sitting there, maybe you could enlighten me on that. Every bike I have owned never reved high at idle and ran fine. 2 turns out it didn't sound like it was taking off and it was running decent. I also have noticed that when i crack the throttle or slow down the idle hangs ;-(.

Take a look at the jetting section and find the jetting sticky there. Give that a thorough read. To summarize the question here, finding highest idle point with the airscrew is simply an easy method to determine if you have the correct size pilot jet installed. It is not a recommendation of where the screw should be located during operation. After you have determined and installed the correct size pilot jet, the airscrew should be adjusted to provide best off-idle throttle response.
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