1993 kx 500 kips valve tuning

[b4himdude]

10 years  ago i blew up my 95 kx500. stuck the rod straight through where the barrel sits on the bottom halves. right below the exhaust hole. so i had  it sitting in storage up until last summer when i found a 1993 kx500 that was for sale at the right price. well it ran well but had ben slightly neglected on the maintenance side. so after using all the interchangeable parts that the 95 i have offered i decided that this year i would rebuild thye 93 and put together another engine for a spare. actually have one running and another to replace it yearly,then rebuild the exchanged for next year and so on. well when i got the 93 open for the first time the exhaust ports for the kips system were so carbon covered the idler gears teeth had been almost totally worn off. pretty sure the thing was inoperable and stick in one position due to the situation. so i bought the parts that i didnt already have from the 95 to replace and rebuild. . as i mentioned the thing ran super with tyhe carbon build up even. so now i have the new barrel and sleeve installed on the 93 bottom end with a new crank rod piston gaskets and everything new that was necessary. but the problem it has even after tearing it down again and inspecting, reassembling and torquing it all down is the low speed to midrange performance is sluggish until i get up in the high rev side of things. i know its got to be the kips system is slightly off not opening at the correct time or whatever but as the clymer book illustrated i aligned it. so any help or insight of anyone who can offer some  on this would be appreciated. ive checked the movement of the assembly and it moves easily by hand prior to assembly of the clutch cover and centrifugal spring  from the crankshaft. i just must have something slightly off and could use a had.  ..please and thank you anybody...

[Foxx4Beaver]

the low speed to midrange performance is sluggish until i get up in the high rev side of things. i know its got to be the kips system is slightly off not opening at the correct time

the KIPS don't fully operate until you're in the upper revs, you can take the pipe off and look up into the exhaust port and see if the KIPS are in the correct "closed" position, and you can pull the rod out while looking up in there too to see if they're opening fully and evenly too ...if you believe you have everything aligned and working correctly as the manual says...I would look elsewhere.
You mentioned the "new barrel and sleeve"...does this mean you had a steel sleeve installed in the cylinder?...if so, were the intake and exhaust ports matched and cleaned up?
How is your jetting?...if you can, find out what your current jetting is and post it here....if there was that much carbon build-up, it may be jetted too much on the rich side.

[Foxx4Beaver]

not sure how much searching you've done on the site...but there's tons of info on KIPS, and getting them set/tuned correctly...

here's a good thread....

http://www.kxriders.com/forums/index.php/topic,8754.0.html

[b4himdude]

you may be right as far as the look elsewhere deal. but the only place left for me to look is the spark plug? the carburetor is ok because as i mentioned i had another (95)kx500 so i always have the option to throw the other carb on to see if that makes the difference. and as far as the sleeve and ports lining up. i bought a brand spanking new never been used cylinder and oem sleeve due to needing one because the 95 stuck the rod through the exhaust side of the case and scarred the old one up pretty bad. so rather than just wait for the 93's to blow up from neglect i chose to use the bottom end from the 93with new crankshaft new bearings bushings   rod washers piston.... you get it everything responsible for the up and down from the combustion  is new . plus i bought a new barrel oem sleeved .cleaned the exhaust valves, guides idler gear and operating rod from the damaged 95 barrel to put in the new barrel. oh plus the main exhaust valve as well. so everything from the crank to the tdc of the piston is new. head was fine so thats not new.  i hate to think that theres something im overlooking. i cleaned the d**n reed valves even. a wet plug might cause this performance issue maybe huh? i would think a fouled plug wouldnt work and a wet one would dry but maybe i went heavy on the two stroke oil and i probably should just filter that crap in with another  fresh 32 :1 mix. i know if theres too much oil it causes the bike to run hot. i dont know. but anyway  to finish off my ramblings i went ahead and bought a crankcase set and all the fixings for it so that when the 93 barrel and sleeve that came out(which was hiding a hairline fracture horizontally on an exhaust port and across the sleeve . as well had a hairline fracture above the wrist pin on the clutch side of the piston. in other words i caught a disaster waiting to happen .... notorious for blowing their own ports and sleeves to pieces. why is that? i guess the racers toy store is going to be getting a couple barrels to repair and sleeve for me sooner or later. its nice to have all these spare parts but if theyd work better together.... ill check that link and do some more homework. maybe its as easy as just too rich on the oil. thank you for  the reply.

[Foxx4Beaver]

I'd still like to know what your current jetting is...just because the carb came off another good running 500 doesn't mean very much, as every bike acts a little differently.

mostly what pilot and needle are you running...and what clip position on the needle.

[KXDINO]

What thickness is your head gasket and what position is your timing on , another thing to look at is lever that pulls the kips rod out is tighten in the correct position also?

[sandblaster]

Just curious, did you check the ohmn specs of the electrical?

http://www.oem-cycle.com/forum/viewtopic.php?f=40&t=163

Out of spec electronics can do all sorts of funny things..
Did you leak down test the engine? Not a compression test, but a leak down?
If you remove the seat, start the bike, put your hand down by the air filter, and rev the engine... do you feel air blowing back through the filter?

[b4himdude]

the answers to some of the questions asked  i will answer ... the main jet is stock 168 the pilot jet is stock 60  the jet needle is stock n82m and its on the second or fourth position. when i got the bike i went up about 2000 feet in elevation. so whichever way it was to do whatever the book said for leaner or richer in accordance to elevation is where i went. for some reason i think i did whatever it took to lean the fuel and richen the air . whichever way that was. t think. i dont remember .id have to go look which would be pretty easy now that i have the barrel off and the exhaust valves out again. i changed all the electrical today other than the stator. so as far as ohms ,no testing did i do but changing the ic igniter and the coil didnt change anything. i also went and got a fresh new 32:1 premix of 91 octane. plus i put in a new b8eg or was it es. i have to check the jet needle clip so ill look at that to.yep b8eg and the jet needle clip is on the second from the top. so yep i leaned her a notch.the stator plate is set just slightly on the advanced side of center. not even half way to the advanced notch line. maybe an 8th off of standard. the head gasket is a tusk oem head gasket i dont have a micrometer handy. because i have another new one sitting in the shipping cardboard still for next time.  but i got a little break on time on her today. it was still kinda chokey in the low to low mid rev range . but when she cleared her throat and really got a lung full for me to sprint through the gears i took full advantage of it. i love how fast you can get through the gears and be hitting fast in a matter of no time. . i probably almost have just shy of two hours on the break in now. not a favorable kind of break in. been apart 3 times now sense the initial assembly. god i just want to figure this s**te out.i appreciate all of everyones curiosity. a little more to the why side you ask all these questions might keep me on the same page a little quicker. im not ruling out anything but when you double up; on all parts stock and rebuild oem,. you would expect it all to be in tune. gotta check that kips thread still. and somebody mentioned putting the lever that pulls the exhaust valve rod "tightened in the correct position??" thats something i never knew had a correct position. just even with the grooved piece on the end of the rod all the way in and tight was what i thought was necessary....plus when the exhaust valves are closed to the port that means the solid backside of the valves are facing the exhaust hole blocking the [port completely off. and open means the slotted side faces the hole and is even is that correct.?

[sandblaster]

Your pilot is too rich.
At 0-1000ft 55 is a good starting point.
I suspect that at 2000 ft you'll probably need to go to a 52 depending on the air temp.
You'll know if your close if your idling good with the air screw at 1.5 turns out.

Set your needle on the mid or 3rd position to start with.
You may need to go to the 2nd position depending on elevation and temps.



You should notice a immediate improvement.

[Foxx4Beaver]

I knew your jetting was way rich!
60 pilot is way too rich...there's a big part of your excessive carbon build-up cause...drop it at least 2 sizes to a 55 to start, and you'll see big improvements!...but I'm thinkin a 52 pilot will be the one you want...especially if you do any trail riding or slow speeds.

[dave916]

To check your pilot
 warm the motor to operating temp.
 Then set the idle {TOP LEFT SIDE OF CARB} so it so it idleing slightly higher than normal
Then turn the air screw{bottom rear left side carb} all the way in  until it bottoms out
Then screw out 1/4 turn at the time, allow 15 seconds between each 1/4 turn for the engine to catch up
Back out  until engine idles at highest rpms
This should be between 1 to 2 turn out
IF it revs highest before 1 turn /pilot lean
If it revs highest after 2 turn / pilot rich
after fitting the correct pilot reset your idle to perfered tickover

s**tty low speed running  can be down to many issues  /air leaks would be top of my list on kx ,case or crank seals,  reeds electrics etc,
No point in chasing jetting issues if everthing else in the motor is not perfect


KIPPS will usually give issue at high rev at it preset it low rev position
To check the kipps timing remove exhuast, disconected kipps rod from governer {tiny circlip}
Look up the exhaust port and pull the kipps rod out/ in this position both kipps valves cutouts will be lined up perfect with the exhauts subports
as u push back in the the rod u shoud see the exhaust subport being blocked, {the may overclose slightly , kawaski decompressor/ search overclosing valve 3.3.2
 http://www.hallbergs.net/kx500/

DONT move the kipp governer by hand on clutch  cover as the internal needle bearing can fall apart

[b4himdude]

just so you know im at 5200 feet. elevation.

[sandblaster]

Yep, your crazy rich for 5000 ft.
You might want to read this:

http://www.oem-cycle.com/forum/viewtopic.php?f=40&t=550

It generally applies to most two strokes but it was wrote specific to the K5

[Foxx4Beaver]

just so you know im at 5200 feet. elevation.

just curious, how does it start?...one or two kicks, or many kicks to get it fired off?...and how does it idle?.
sounds like you've covered most everything else except the jetting.
change your low speed jetting.
99.9% of the time when someone says their bike is running s**tty/sluggish at low speeds, it's because the pilot is too big for their conditions, and/or the needle clip is in the improper position, and usually a different needle is required for fine tuning....and since you said you've gone up another 2000ft in elevation after you got it...well you know where I'm going with that.  
it wouldn't hurt to do a leak down test like Blaster mentioned, since you've had it apart and back together...but I'm thinkin you'll find your problem in the carb.

[b4himdude]

ok i looked at the link for jetting and i took the slow jet from 60 to 58 . judging from the conditions of the high end rev being spot on and the table in that very informative jetting guide  i was linked up with  showing my jet needle clip should be exactly where i have it for temperatures as we are coming into. i may want to lean out the slow jet a bit more . but  a 58 is definitely in the range for my elevation. maybe a bit warmer and then a leaner by another couple might be in order. but i had a 58 laying around so a 58 is no cost and no trip down to 5th gear bike shop at the other end of town. plus its monday... no bike shops are ever open monday...are they? as i was asked how the bike starts/ idles / i forget what else .oh a leak down test. once i get it back together ill do that post haste. but for now ..heres how the other two questions get answered. starting - im not going to say ALWAYS but 99% of the time when i get the kick starter all the way to the top (a full good hard kick).   since i rebuilt it other than when i tested it in the other frame mounted to a board which doesnt really count have  i had to kick it more than one time to fire it up. yesterday i  kicked it off balance and didnt get the full kick at it on the first try and had to give it a second kick. so first kick choke on but off immediately after it goes. idling.. when its cold it idles till warm when its warm it idles but the cap cable adjuster cant go too much further before it runs out. but i can get a high idle if i adjust it that way. i dont like a high idle.  .but without the cap adjuster the idle air mixture screw doesnt seem to do anything too much one way or another.  . but lets see after the slow jet i just put in does its job.maybe thatll solve the issue or show promise in the right direction. at least i was too rich. thats the better side at least. well better for not welding the rod to the shaft. i  wish i had a picture of how the exhaust rods look in the barrel port from a view from the pipes hole when  the bike is off and how the operating rod end is  in conjunction with the pull lever thats held on by that 10 mm nut to the shaft that sticks out from the clutch cover. just so i can be 100% certain that i have the clue i know what im doing on that. until i know something by doing it myself and getting the result desired......then i know nothing about it and  i dislike not feeling confident about something. i think utube should have a simple  video on that. they have one but somebody is actuating the rod with a wrench and you can barely seen the main exhaust valve. that ois the biggest waste of video for the effort put into it. the main valve can only go in ONE way. its the two rod style ones that have marks to line up to another make and a right and a left side valve that mean everything to  the system . just a picture with a bike off ,a pipe off ,a lever position with the plastic cover and rubber boot off so a person can see how far the rod is out and the lever is angled ,and the other picture of the right side valve position and left side position with the same bike off and not  touched  that way i know where to set it all. 3 pics maybe. i just dont know for sure on that. seems like theres only one way it can go. but somebody said something about the lever position and then tighten .. which leads me to believe there is some adjusting that can be done after assembly. but will also lose some of its full open or closed end . one way or the other. anyway oiu have to go guess at this thing one more time. thats where im headed now to do it the same dang way ive done twice before. how the book te;lls me. you know oits kind of questionable on that clymer447-3 book when it says line the marks on the exhaust shaft gears to the marks on the operating rod and then illustrates both marks off just slightly. wtf is that??   believe  what i read but refer to figure 100 on page 1439 to see the picture and confuse myself. high performance must be exact. who edit those books. somebody needs to see if they can catch a bullet then illustrate it for me.
thanx guys. dont give up on me yet.  from what ive read that youve shared  i am very appreciative. how can i post a pic of my bike. you may be pleasantly surprised on how much ive done to my stock thumper...