Mid Range Jetting

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madozzie
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Mid Range Jetting

Post by madozzie »

Hi, got my new (old 1998) KDX200 a week ago. Not much history on it. First one I have owned and love it. Cleaned the carbie thoroughly and set float. It came with a 160 main and 48 pilot with clip in third from top on needle. FMF Fatty Pipe & Powercore . Seems to run fine past idle and there lies the problem. I am having to screw the idle screw in almost all the way to get it to idle OK. The air screw seems to do bugger all. Read heaps of threads on this topic and it seems that people spend more time screwing around with jet sizes and mixtures than they do riding and still are not happy. At $25 a jet in AU I am not interested in buying a swag of jets to trial and error them.

I don't race and am not looking for peak performance. I just want it to start easy and get going.

Is this jet and clip position OK for what I want or is there a better mid range jet size that is more forgiving and will work across a wide range giving average performance but less trouble?. Any ideas why the idle screw needs to be in so far? Did I mention the carby and jets are squeaky clean :) Altitude is about 1000ft (apparently that makes a difference) and temperature is about 20deg Celcius on average.

Any comments are welcome.
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KDXGarage
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Re: Mid Range Jetting

Post by KDXGarage »

Have you checked the condition of the reeds?

ALSO, welcome to the forums.
Thank you for participating on kdxrider.net. :bravo:
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JasonK94Z
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Re: Mid Range Jetting

Post by JasonK94Z »

2002 KDX 220R
2003 KLR 650
madozzie
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Re: Mid Range Jetting

Post by madozzie »

haven't checked the reeds....yet. Waiting for the workshop manual to arrive to show me how to do it then will get to that. From what I have read here it seems that jets are the most probable cause but I don't really know if what I have is workable or do I have to go with smaller jets. They cost a small fortune here so not keen to play around with different sizes if I don't have to.
madozzie
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Re: Mid Range Jetting

Post by madozzie »

Thanks Jason, I think you were on the right track with the reeds. Checked them today. One side has curled up a bit leaving a permanent gap of around 0.7mm at the tip. I flipped it over. Strangely there is still a small gap of about 0.3mm (I thought flipping it would seal completely). Started after second kick and runs much better at idle. Idle screw needed backing off 2 full turns now. Got new reeds ordered so this will have to do for now.

Re the jets, the manual says stock is 160/48 with needle in 3 clip down just how I found it. This is within the FMF pipe website recommendations so I will leave it until I see how the new reeds go when I get them.
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Re: Mid Range Jetting

Post by KDXGarage »

SWEET. I am glad it worked out.

You have a good idea to just change one thing at a time.
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