jetting questions

Discussion specific to the 1995 - 2006 KDX200 (H Series) and 1995 - 2005 KDX220R (A Series) models sold in the USA
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actmobmar
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jetting questions

Post by actmobmar »

i just got this bike, 01 kdx200. it appears all stock with the exception of an fmf gnarly pipe and powercore silencer, and foam air filter. bike definetely runs rich, soggy midrange, and ok top end. it currently has a 155 main and 45 pilot, air screw out 3 turns, needle clip at top position. i changed the pilot to a 40, put the clip in the middle, and set the air screw to 2 turns after running it. it idles good but smike then i consider normal, doesn't free rev well and gives a loaded up feel before it clears up and goes, but not great. it also has boyessen reeds. i'm thinking about putting a 152 main in it, and moving the needle clip up one position from the middle. any suggestions?
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Julien D
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Re: jetting questions

Post by Julien D »

Yep, start here. No shortcuts! Throwing random jets at an engine without the proper process is pretty much like pissing in a fan. :)

http://www.kdxrider.net/forums/viewtopi ... 105&t=1156
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bufftester
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Re: jetting questions

Post by bufftester »

Julien D wrote:Yep, start here. No shortcuts! Throwing random jets at an engine without the proper process is pretty much like pissing in a fan. :)

http://www.kdxrider.net/forums/viewtopi ... 105&t=1156
+1 Follow the guide step by step and don't get tempted to shortcut. It works every time, all the time.
actmobmar
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Re: jetting questions

Post by actmobmar »

i put a 37 pilot in it last nite, and set the float level and cleaned the carb. it still is rich at idle, and starts cold(88 degrees) without using the enrichener. if i turn the air screw in i can kill the engine, it idles ok at 1.5 turns out or more, but going 1.5 out doesn't seem to have any effect. i raised the needle clip to position 2(second slot from top) and that helped a lil with midrange cruise. also, airbox has half the lid cut open. am i missing something here, i thought changing the pilot to 37 would've made a difference.
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Jaguar
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Re: jetting questions

Post by Jaguar »

You also have to fiddle with the idle circuit for good running when putting along in 1st gear and how well it begins to accelerate when you gradually open the throttle. Put a leaner R1173N needle in it for cleaner mid range running.
Performance CDI -- KDX motocross mods -- the SR KDX -- expansion chamber analysis---> http://www.dragonfly75.com/moto/
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KDXohio
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Re: jetting questions

Post by KDXohio »

+1 on the jetting guide
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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