KX Riders
Maintenance & Technical => KX500 Original => Topic started by: no sub for cubes on March 06, 2009, 03:09:11 AM
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HI guys
just recently got my bike to started after putting it back together,ive got it running about 3 weeks ago and it started fine revved cleanly after warmed up and i was able to adjust the idle screw to get it ticking over for about a min,i started it up today give it a blast up the road a couple of times and then noticed it smoking loads even though hot,its started idling uneven surging and turning the idle screw all the way out it still idles :?...now i bought the bike as a basket case and the guy told me the motor had been completely rebuilt,i had no reason to doubt him as the piston looked new and the gaskets round the cases looked new...im just miffed why tonight all of a sudden its smoking badly and it idles(eratically) even when the idle screws wound right out?it worked fine before and i had to adjust it in the get it to idle...the jettings main:175 pilot:65 needle pos:3 air scews 1 half turns out ,any insight would be appreciated.
simon
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just had another quick look,started up ok and have noticed oil leaking from behind the front sprocket........alls not looking well :-(
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HI guys
just recently got my bike to started after putting it back together,ive got it running about 3 weeks ago and it started fine revved cleanly after warmed up and i was able to adjust the idle screw to get it ticking over for about a min,i started it up today give it a blast up the road a couple of times and then noticed it smoking loads even though hot,its started idling uneven surging and turning the idle screw all the way out it still idles :?...now i bought the bike as a basket case and the guy told me the motor had been completely rebuilt,i had no reason to doubt him as the piston looked new and the gaskets round the cases looked new...im just miffed why tonight all of a sudden its smoking badly and it idles(eratically) even when the idle screws wound right out?it worked fine before and i had to adjust it in the get it to idle...the jettings main:175 pilot:65 needle pos:3 air scews 1 half turns out ,any insight would be appreciated.
simon
i don,t know what to say ,but want to try to help here.
couldn,t it be the rightside crankseal blown out ,causing gearbox oil to burn in the combustionchamber,causing severe smoke ?
is it maybe possible all together ,compression is pushing gearbox oil against the frontsprocketsealing ,causing it to leak ?
that is possible if the drain on the top ,located behind the kickstarter,could be possibly be clogged ?
i ,m just thinkin out loud
still the high idle is weird ,
i had experienced the above crankseal story with a kx250 ,
but it didn,t idled irraticaly like yours does :|
hopin for more input here!!
curious now .
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Could your dryseal be leaking? High idle seems to refer to an airleak. A bad wetseal on the crank could cause smoking. Smell the plug. If it smells like gearlube you have a bad seal.
If i were you i would replace the seals. :roll:
My friend had same kind of symptoms in his bike. We replaced all the seals and it ran great!
-J
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Could your dryseal be leaking? High idle seems to refer to an airleak. A bad wetseal on the crank could cause smoking. Smell the plug. If it smells like gearlube you have a bad seal.
If i were you i would replace the seals. :roll:
My friend had same kind of symptoms in his bike. We replaced all the seals and it ran great!
-J
yea it seems a paradox?
high idle and smoke ,but you make things clear ,thnks
freak
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i checked a buddy who is racing cr5
he told it,s definately crank seals
dry one causes high idle
wet one lets oil flow back n forth ,causing smoke,
and causing fs seal to leak due to clogged drain .
they were not new seals i think :roll:
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cheers for the replys guys
ive looked behind the fly wheel cover to check for oil residue as i read on here this was a sign that the dry seals had gone and its completely dry in there...when i say its idling bad i means its surging on idle not really high just not healthy....and adjusting the idle screw did nowt it still ticks over when its wound out,something i did fail to mention which prob does have some relavence is the gear box seemed to go really tight hard to select a gear and then freed up again,after that it started smoking badly and ive noticed oil leaking from the sprocket...i really need to pull the sprocket off tomorrow and confirm.as for the plug i pulled it out still looks pretty clean but again not really run it alot since build.
So is there signs to look for the crank seal gone? i need to do a bit more investigating myself to give you guys a bit more info but really appreciate the prompt replys
cheers
simon
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A crankcase pressure test should be performed after a rebuild. It will show if something is leaking. Block the exhaust ( can be quite tricky because of the powervalve) and pump pressure trough intake. 5 psi is good. Normal pressure loss is one psi per minute, so the pressure should last about five minutes.
Edit: The flywheel side seal causes engine suck in air when seal is damaged or failed. You can test it by putting some babypowder over the seal and kicking the bike running. If it gets wet or dissappears you've got a bad seal.
-J
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cheers jopiz
its looking like the crank seals gone on the wet side the symptons are as kx freak described smoking like a ***** and oil leaking from fs......wounded!! but i will defo look at doing a leak test before i pull it apart!
Well you live and learn not to rely on other peoples integrity,i should of had a proper look over the motor before dropping it in.
much appreciated guys
great site and great people willing to share knowledge
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simon ,i learn all the way too here.
that,and the chance too try help one fellowkxrider out,
is the essence of kxriders imo :)
so pleasure,s al mine here and good luck on the repair !!
keep us posted :wink: