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1993 kx 500 kips valve tuning

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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:

--- Quote from: b4himdude on June 06, 2015, 07:51:48 PM ---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

--- End quote ---

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.

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