Kevenater

anybody good at jetting a kx 500??

25 posts in this topic

I can't get on kxriders.com cause the registration is closed cause of cyber attack. there is huge thread on there about jetting the 500 and they figure out the jetting on everybodies that is having trouble. too bad i can't get on there which is retarded. anyway i just got the 03 this past friday. the main jet in was a 152 for some reason, i cleaned the carb and put the stock 168 main jet back in it, the pilot is 55 and the needle is stock. i changed the air filter and checked the plug, it looks pretty decent, not perfect. first and second gears are pretty peppy, 3rd is ok when u first get in it, kinda weak on the mid and top, 4th and 5th won't even think about pulling the front up anywhere. i test rode an 86 kx 500 a couple weeks ago and you couldn't hold the front end on the ground at any speed in any gear unless you barely twisted the throttle. from what I read that's how they're supposed to be! I want mine like that. gotta get this figured out. if only i could get on kxriders and talk to those guys in that thread. oh and it also surges, mostly when you let off the gas.

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that's the thread i've read from start to finish but I cant participate cause they've got the stupid registration closed. that's my exact setup but I'm at 890 feet elevation.

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that's the thread i've read from start to finish but I cant participate cause they've got the stupid registration closed. that's my exact setup but I'm at 890 feet elevation.

I'd go with a 170 main to start.

Move the needle up 1 or 2 which is moving the clip down to raise it.

If your bike does not respond to air screw adjustments then you may have to go up on your pilot too. I'll go dig my Clymer out I think there's a chart in there also.

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thanks pegger, does yours try to run out from under you in any gear with any amount of throttle?

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it almost feels like my cr 250...seriously

Sounds like maybe the KIPS is acting up if it's that bad. The bike will run somewhat OK but with no power? Pull the KIPS plastic inspection cover off and start it up. See if the actuator rod is moving in and out when you cycle the throttle! If it doesn't move or very little something is wrong or gummed up.

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it has power, i mean it's not bogging or anything, but it's NOWHERE near what that junky 86 kx 500 i test rode a couple weeks ago. that thing scared me to death!! i can feel the power valves opening but it just don't have anywhere near what it should! it doesn't scare me any at all except a little in first and maybe a little in second. i haven't ridden in a few years even though i have a 99 cr 250. it has just been sitting in the shed so i'm not used to any of them. i'll check the power valves first chance I get as you say. how far should they move?

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Im running a 162m, a 55 pilot with the needle in the 2nd from last position leaner. Air screw is 2 turns out with 40:1 110 octane fuel. My float was off on mine and was dribbling fuel out of the overflow when leaned over slightly. It was running a little rich up top also. I adjusted the float and there was a noticeable improvement throughout the powerband. Mine is a 02 500 in a 04 250 2t chassis. I had to use the 250 intake and a Vforce 2 from a 250. They are a little smaller and restricts flow some. Mine runs similar to yours but has very strong bottom and seems to flatten out up top some. I attribute it to the 250 intake. I like it because its mainly a tight woods bike and has been working very well in its current set up.

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I don't get why they are so hard to jet right.. they're supposed to scare you to death with the slightest throttle in all 5 gears!!! that's how the 86 was other day and my friend told me today that he rode a cr 500 several years ago and it was the same way. couldnt even touch the gas hardly and he was leaning over the bars. this sucks!!!! right now i pretty much regret wasting $2000 on it. If/when It's fixed I won't regret it anymore. I have to have a different problem I think.

Edited by Kevenater

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oh and if anybody has a membership on kxriders.com can you please contact a moderator and see if they can let me register PLEASE!!! they are the only ones that seem to be able to figure this mystery out and I can't even get on there to get their help....

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I used to race a 88 500 in 88-89 and it felt similar to my current bike. It didnt really scare me, actually no 500 that Ive ridden really scared me. Theyve all been smooth, easy to ride bikes. I did ride a brand new 86 back in the day and it did have a harder hitting powerband.

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so they didnt try to run out from under you with just a slight amount of gas? that's weird. wonder why the 86 and that cr500 my friend rode both did? hell there is NOTHING impressive whatsoever about mine as it is right now. very disappointing actually. no way it's right. if it was then that 86 would have had to be a 1000cc 2 stroke to be that much more powerful

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i know on the kxriders.com jetting thread it was mentioned that most kx 500's are only running at 60-70% of their true power due to wrong jetting.

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Hey everyone! I have a 97 500 and I'm trying to get it jetted properly! 

168 mqin

55 pilot

the idle is high and doesn't change when I mess with idle screw or air screw. Suggestions?

was thinking of going up on the pilot 

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31 minutes ago, Conner_Steezel said:

Hey everyone! I have a 97 500 and I'm trying to get it jetted properly! 

168 mqin

55 pilot

the idle is high and doesn't change when I mess with idle screw or air screw. Suggestions?

was thinking of going up on the pilot 

What is your approx elevation? How high of an idle is it? Sounds like it could be leaning out at low rpms so yes try messing with maybe the needle position first and if nothing then try a size up on the slow jet. I had a 86 KX500 and if I remember right you could adjust the actual cable at the bars so it basically adjusts the slide in the carb at idle. Also something to think about but I am not sure if you can adjust the cable on a 97.

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7 minutes ago, TheKX500boi said:

What is your approx elevation? How high of an idle is it? Sounds like it could be leaning out at low rpms so yes try messing with maybe the needle position first and if nothing then try a size up on the slow jet. I had a 86 KX500 and if I remember right you could adjust the actual cable at the bars so it basically adjusts the slide in the carb at idle. Also something to think about but I am not sure if you can adjust the cable on a 97.

I am at sea level. I will look into the cable adjustment. And I will try needle position. It's at 3rd clip right now. Thanks for reply 

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