Runs for :90 sec,HELP!!!

[connie]

My KDX 200 has less than 5 hrs. on it. It runs for about 90 sec. and wet fouls the plug. If I clean the plug and put it right back in it will run for about 90 sec. and produces much smoke. It is the correct plug and I have replaced it three times with the same results.
premix is 40:1, Klotz R-50
main jet is 155
pilot jet is 45
clip is 2nd down from top
air box lid removed
elevation is 250 ft
temp has been in 70's

I am hoping to tap into all the expert advice I see on the site. I am out of ideas.

 

[TimberPig]

If its fouling the plug out like that, your jetting may be off, the inlet needle and seat leaking or dirty, a float punctured, your clutch side crank seal could be leaking, the crankcase could be flooded, or the spark weak, and more susceptible to being fouled out. Start tracking these down, and your answer should appear.

 

[Rhodester]

More than likely your float/needle and seat is hanging up somehow. Just pull your carb apart, clean things up, and reset your float level and try it again. BTW, do you have your choke on (and on, and on...)? Is your air screw somewhere around 1 1/2 out?

 

[GS]

My KDX 200 has less than 5 hrs. on it.

5 hrs. from what? from a new top end?.....from brand spankin new? Did you have experience with this motor before this happened? Any recent changes that will provide clues?
Are you familiar with the operation of the choke in relatively warm(70 deg) weather?
New gas/old gas?

So....give us a ... :clue:

 

[Papakeith]

bad crank seal sucking trans oil.

 

[connie]

Thanks gents:
The bike is a new left over 2005. The bike is new, the gas is new,the choke is off ,and the airscrew is out about 1.25 turns.The first day It ran just fine. I did the break-in per the book.The second day it ran fine. Before the third ride I removed the air box lid. All the problems started after that. I removed the stock jets and put in the 155/45 to no avail. Thanks for the ideas so far.

 

[krazyinski]

Thanks gents:
The bike is a new left over 2005. The bike is new, the gas is new,the choke is off ,and the airscrew is out about 1.25 turns.The first day It ran just fine. I did the break-in per the book.The second day it ran fine. Before the third ride I removed the air box lid. All the problems started after that. I removed the stock jets and put in the 155/45 to no avail. Thanks for the ideas so far.

Me thinks go back to stock and see if your problem goes away sounds like its to rich. mine has all the fredette mods including a bored carb and a pipe and I am running 160/45 I am changng to 155 cause its to rich.

 

[KDX CRAZY]

If all you did was lean the jetting and move the clip on the needle then your problem must be in the carb , take the carb apart and make sure everything is in properly .
I run at much higher altitude with standard jetting from factory and dont have any fouling problems .

 

[John Harris]

Are you putting in new plugs or just replacing with cleaned old ones? If you are putting in brand new ones, try a different batch of new ones. Most likely the problem is in the carb, and it will go back together with the float valve not in its correct seat. Don't ask me how I know this. Anyway reassemble the carb carefully and you will probably find the problem is cured. By my experience you are still jetted rich on the primary. Cheers John

 

[Green Hornet]

Check the float assembly (att. to the pin). Those things fall off without even realizing during the re-install.

 

[css_elfers]

Is it still under warrenty? If it is take it to the shop and tell them to fix it. Return it back to stock of course.

ELF

 

[matt-itude]

A vote for a float problem. Also double check your jets not just by number but to make sure you dont have a mismarked or drilled jet in there.

 

[nanddm98]

put everything back to stock and see what happens

 

[Rhodester]

It's the float. Keep your new jetting and just reassemble with care. No need to over think the problem.

 

[skull creek mx]

did anything get left inside the airbox that shouldn't be there?