KX Riders

Maintenance & Technical => KX500 Original => Topic started by: Rulingtheroost on August 14, 2016, 09:16:50 AM

Title: 93' kx 500 rich in 1st 3/4 throttle
Post by: Rulingtheroost on August 14, 2016, 09:16:50 AM
Hi I just picked up a 93' kx 500 new top end fmf fatty pipe n silencer test rode it real fat had a hard time clearing it out has stock jetting 168m 58 p 3rd clip neddle. So I started looking checked reeds looked good no cracks fliped 1 went to 165 m 52p 1 clip leaner on neddle set air screw 2 turns out bel ray 40:1 110 av gas rode it better but still not right played with air screw got better the more I turned it out I'm at 4 turns out now and thats to far also 95 deg. and humid whats your thought oh btw runs awsome on main
Title: Re: 93' kx 500 rich in 1st 3/4 throttle
Post by: Foxx4Beaver on August 14, 2016, 09:33:52 AM
4 turns out on air screw is no good.
what's your elevation?
what needle are you running?
have you done a leak down test to be sure you don't have an air leak?

base point is...

168 main
55 pilot
3rd clip on needle
roughly 1 1/2 to 2 turns out on air screw.
Title: Re: 93' kx 500 rich in 1st 3/4 throttle
Post by: Rulingtheroost on August 14, 2016, 10:11:26 AM
Around 1200' northeast pa. adjusted float height went to 48 pilot
Title: Re: 93' kx 500 rich in 1st 3/4 throttle
Post by: Rulingtheroost on August 14, 2016, 12:02:24 PM
Just put a 48 pilot now hangs on idle and idle screw does nothing adjusting air screw helps with the fat middle but makes idle higher going back to 52 pilot there's got to be something wrong ie bad reed float height needle jet holder? 
Title: Re: 93' kx 500 rich in 1st 3/4 throttle
Post by: Foxx4Beaver on August 14, 2016, 12:03:22 PM
could be a worn needle seat.
Title: Re: 93' kx 500 rich in 1st 3/4 throttle
Post by: Rulingtheroost on August 14, 2016, 12:29:14 PM
could be a worn needle seat.
Those suckers are pricey think I saw $65
Title: Re: 93' kx 500 rich in 1st 3/4 throttle
Post by: Foxx4Beaver on August 14, 2016, 12:34:30 PM
it's common on the older bikes....I went through it on mine too...eventually I got disgusted enough, and just bought a brand new carb from Sudco.
Title: Re: 93' kx 500 rich in 1st 3/4 throttle
Post by: Foxx4Beaver on August 14, 2016, 12:47:10 PM
I'm not saying you should run out and buy a new carb yet...not until you've actually pin-pointed the cause of the issue, there could be other under-lying problems that need to be ruled out 1st...before spending $300+ on a new carb.
Title: Re: 93' kx 500 rich in 1st 3/4 throttle
Post by: Rulingtheroost on August 14, 2016, 10:01:22 PM
Been doing some reading and a  comon ethenal related issue is this o-ring goes bad http://www.ebay.com/itm/Jet-block-o-ring-Keihin-PWK-33-41-carburetor-35-36-38-39-40-mid-body-gasket-/201306545569?hash=item2edece1da1%3Ag%3A-hgAAOSwqu9VAecS&vxp=mtr
Title: Re: 93' kx 500 rich in 1st 3/4 throttle
Post by: Foxx4Beaver on August 15, 2016, 07:23:38 AM
yeah...that corn fuel is bad stuff...and will tear things up if it sits around in a carb/fuel tank too long.
it bit me last year, and plenty of other guys too over the past decade....
http://www.kxriders.com/forums/index.php/topic,14782.0.html

now I only run straight C-12.
Title: Re: 93' kx 500 rich in 1st 3/4 throttle
Post by: Rulingtheroost on August 15, 2016, 09:31:08 AM
Been doing some research and it looks like the choke circuit could be leaking causing my rich condition and the fact the idle screw has no effect on rpm