93' Klx650 blue clouds of smoke when cold starting

Hi all,

I have a problem here that i'm trying to figure out at the moment on my 93' Klx650C. When i'm cold starting the bike, it's blows a cloud of blue smoke for the first 30 seconds with the choke on. It only happens for the first 30 seconds with the choke on after that it runs normal....anyone would have any idea?? 

generally speaking you need to take a look at your valves

when was the last time you checked them out/adjusted ?

 

blue smoke on startup  generally indicates worn valve seals or valve guides or both

a little bit of oil leaks and passes guides and goes into the combustion chamber over night or after a long stop (if you dont ride it for a few days) and then when you first fire up the engine that small amount of oil gets burned generating the blue smoke. the leak is so small, it cant be noticed when riding normally but when bike sits long enough it accumulates enough to make it smoke. Have you checked your oil to see if gets any lower over time.
 

generally, blue smoke mean oil leak, white smoke means radiator fluid leak.

you can google it there are many threads about it. it's not specific to KLX650 many other bikes have similar problem. Good luck!

My '96 did that when I bought it with 23k miles on it , each time starting after sitting overnight and longer it would smoke for 20-30 sec and then quit , I know the valve seals are bad . However now that I've owned it for a few years and ride it frequently (even though I have 6 bikes currently) It has almost stopped doing it . If I start it in the garage I can smell burnt oil some but no haze or smoke anymore. I honestly feel it is the type of oil I use in it that has softened up the seal so they seal better now . The rings are getting worn so it does burn oil that way but it's not bad as far as how much oil I need to add between oil changes . No proof of this and not saying this oil is better than that oil , it's only what mine has done but maybe try a different oil and see if it gets better , not out anything and if it stays then time for valve seals . This isn't the first time I've bought a bike that had some issue that went away magically after changing to my fav oil.

 

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On 8/12/2017 at 11:31 PM, jjktmrider said:

My '96 did that when I bought it with 23k miles on it , each time starting after sitting overnight and longer it would smoke for 20-30 sec and then quit , I know the valve seals are bad . However now that I've owned it for a few years and ride it frequently (even though I have 6 bikes currently) It has almost stopped doing it . If I start it in the garage I can smell burnt oil some but no haze or smoke anymore. I honestly feel it is the type of oil I use in it that has softened up the seal so they seal better now . The rings are getting worn so it does burn oil that way but it's not bad as far as how much oil I need to add between oil changes . No proof of this and not saying this oil is better than that oil , it's only what mine has done but maybe try a different oil and see if it gets better , not out anything and if it stays then time for valve seals . This isn't the first time I've bought a bike that had some issue that went away magically after changing to my fav oil.

 

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The worst time of when it blew a lot of smoke was the time i used the repsol 10w40 (I don't do Repsol, Only Lucas!!!) because i ran out of Lucas 20w50 for about 3 weeks. I dropped the oil right away as soon as my Lucas stock arrived in a parcel. Didn't take nothing apart. I keep riding it since then and the oil pretty much eliminated the smoke problem. I think it's like you said it could be the type of oil i'm using that the bike just doesn't like.

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