Bookmark this:
http://www.buykawasaki.com/site/VIVehicleInformation/VIChooseVehicle.asp?intCatalogID=2&intParts=1
Take note this is NOT the 'front page' of the site..but the info lookup page per make/model/year.
From this site you can find that the stock jetting for your bike is 48/150.
re: 'My jet sizes are as follows 58, 155, 172'
No they aren't. You don't have three removeable jets...only two..pilot and main. In any case, if any combination of those jets are in your bike, it is so far off you can't even SEE your bike from here (probably due to all the smokin')!!!
re: Is this ok for 5k+el.
What Gearloose said.
A
premix ratio change to 40:1 from 32:1 is making your air/fuel mixture more rich, making an already bad situation worse.
In the 'Every KDX rider should read this...' stickied to the top of this forum you (and everyone else) will find a link to Canadian Dave's website. I would suggest that every KDX rider read it. ...for all of you that haven't asked, consider yourselves to have received anyway.
re: Can a bad crank seal cause this problem (smokin').
Yes.
A change in plug heat range to address a poorly jetted bike is for sure a misstep in the wrong direction.
A 'needle jet' and a 'jet needle' are two different things. A jet needle fits inside the needle jet. The jet needle sits inside the throttle valve. Most Keihin carb needle jets are not replaceable through average means. Keihin needle jets are rarely changed/tuned for that reason.
There is an altitude jetting compensation chart on CDave's site.
Cheers!