Author Topic: Kx 500 help  (Read 9690 times)

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Offline troy_68

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Kx 500 help
« on: October 09, 2011, 04:48:53 PM »
I recently rebuilt my 1996 kx500 and it runs good but it seams to be slow. it has 190 lbs of compression i run 93 octane gas. and i am barley able to pull away from my buddys kx 250. i also have a fmf exhaust system and uni air filter. any help would be much appreciated.
Troy

Offline jonny500

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Re: Kx 500 help
« Reply #1 on: October 09, 2011, 05:14:50 PM »
blocked exhaust or power valve operation/timing. a couple of things to look at

Offline kwakman

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Re: Kx 500 help
« Reply #2 on: October 09, 2011, 08:53:54 PM »
jetting and/or ignition if compression is good.also, carb blockages, dirty air filter, fuel flow valve height are some others.K.
And lo, I did loft the front wheel and carried it forth to the unbelievers, and cast it down before them and said unto them ''look now upon the might of my throttle control ye pitiful cretinous ones''
And the unbelievers did quake in their boots....

Offline Friar-Tuck

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Re: Kx 500 help
« Reply #3 on: October 10, 2011, 03:42:24 AM »
Welcome Troy,
Thanks for signing up to the site, now lets see..
  Unless your cousin only weighs 80lbs and has or has an ex-pro's 250 something does sound suspicious...  If the engine is running o.k., move the Kips plastic /rubber cover out of the way and see if the rod and lever are moving when you rev the bike.
  You should be able to see the rod moving as the engine rpm increases. 
  Tuck\o/
"The Truth Has No Agenda"

Offline husky333

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Re: Kx 500 help
« Reply #4 on: October 11, 2011, 05:07:24 AM »
occasionaly the circlip comes adrift on the powervalve actuating arm, this disengages the powervalves. Its a simple fix, look behind the rubber cover on the outside of the barrel behind the front pipe. :wink:

Offline troy_68

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Re: Kx 500 help
« Reply #5 on: October 12, 2011, 06:19:41 PM »
Thanks for the ideas ill be tearing into it in the morning to see if i can find a solution. I really dislike barley being able to beat a 250...
Troy

Motorrad

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Re: Kx 500 help
« Reply #6 on: October 13, 2011, 12:35:35 AM »
I recently rebuilt my 1996 kx500 and it runs good but it seams to be slow. it has 190 lbs of compression i run 93 octane gas. and i am barley able to pull away from my buddys kx 250. i also have a fmf exhaust system and uni air filter. any help would be much appreciated.
Troy

190 PSI of compression...   on 93oct... HMMM....  Somthing there doesnt add up,    :|

Is that Oiled or not oiled?  (some drop oil down the Plug hole before test, which gives a false high reading sometimes)

Has the head been cut? Barrel been decked? what is your Head volume?   Deck hight? and squish clearance?  And Which FMF pipe?

Positive you installed the Kips correctly?   Using the wrong base gasket can also cause you to lose roughly 1mm of exaust port time off the kips flap....
« Last Edit: October 13, 2011, 12:40:38 AM by Motorrad »

Offline troy_68

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Re: Kx 500 help
« Reply #7 on: October 13, 2011, 01:22:23 AM »
Friar-Tuck you were right i pulled the plastic cover off and started the bike and when it was reved the levers never moved. so next question how do i fix it?
Troy

Offline 1989kawasaki

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Re: Kx 500 help
« Reply #8 on: October 13, 2011, 06:51:15 AM »
are you able the move the rod manually with out the engine running?

Offline husky333

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Re: Kx 500 help
« Reply #9 on: October 13, 2011, 08:38:23 AM »
The powervalve actuating arm has a tip on it that should sit in the groove of the Kips wheel. check to see that the powervalves are opening and closing manually before re connecting the system. the actuating arm sometimes comes adrift because the tiny circlip that holds the wheel in place has fallen off.

 I recently rebuilt my `88 kx5 and had the same problem, i found that the tip of the actuating arm wasnt engaging the wheel correctly,(although the circlip was still in place), so i carefully bent the actauting arm forward until it sat in the groove on the kips wheel properly. it only takes a few minutes to fix,.. and is really obvious what to do,( i knew nothing about such things when i found my powevalve not operating properly), a friend told me over the phone what to do,... no special tools needed! :wink:

Offline troy_68

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Re: Kx 500 help
« Reply #10 on: October 13, 2011, 06:32:38 PM »
fixed it. the arm wasnt moving at all and i pulled the clutch cover off and whatever the part that hooks up to the power valve was improperly installed. So i put it in correctly and now I feel i have one of the most powerful dirtbikes ever made. Id like to see how it does against the newer 450's i ride mostly trails in northern Mich. Thanks again for all the help!
Troy

Motorrad

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Re: Kx 500 help
« Reply #11 on: October 14, 2011, 12:22:23 AM »
I recently rebuilt my 1996 kx500 and it runs good but it seams to be slow. it has 190 lbs of compression i run 93 octane gas. and i am barley able to pull away from my buddys kx 250. i also have a fmf exhaust system and uni air filter. any help would be much appreciated.
Troy

190 PSI of compression...   on 93oct... HMMM....  Somthing there doesnt add up,    :|

Has the head been cut? Barrel been decked? what is your Head volume?   Deck hight? and squish clearance?

Something you still need to adress.....

Offline troy_68

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Re: Kx 500 help
« Reply #12 on: October 14, 2011, 08:25:30 AM »
When I did the check the engine had just been warmed up and I didn't drop any oil in. The cylinder I sent  out to be sleeved and I do not think either were shaved down, so I'm unsure as to why there is so much compression. The bike runs amazing though

Offline Friar-Tuck

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Re: Kx 500 help
« Reply #13 on: October 14, 2011, 02:45:35 PM »
Hey Troy,
 Glad you were able to get your bike running better, nothing like that rush of power and
 a grin under that helmet from ear to ear :-D

  I think Motorad is concerned about the compression leading to detonation with that much pressure and 93 octane.
Is that Right Motorad?
   Tuck\o/
"The Truth Has No Agenda"

Offline turdle

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Re: Kx 500 help
« Reply #14 on: October 17, 2011, 01:19:28 AM »
fixed it. the arm wasnt moving at all and i pulled the clutch cover off and whatever the part that hooks up to the power valve was improperly installed. So i put it in correctly and now I feel i have one of the most powerful dirtbikes ever made. Id like to see how it does against the newer 450's i ride mostly trails in northern Mich. Thanks again for all the help!
Troy
where in n. mich do you ride? i ride between lupton and mio. T