2002 kawasaki kx250 ...... just picked it up....

[Dirt Addict]

i just picked up a 2002 kx250.  does anyone have some jetting reccomendations?  any quirks or things that need to be watched?

[MyckMcClung]

I have plenty, but due to the lack of specific facts you have provided, I am unable to provide specific specs.
Altitude in which you will be riding
oil/fuel ratio
Pipe type, silencer length
other modifications, such as reed blocks, cylinder porting...
Thanx you come again.

[keeptwostrokesalive]

Pictures

[Dirt Addict]

alt  1k' - 4k'  (most often around 3k')
oil 32:1
fmf gold pipe / tc II muffler
stock cylinder and reeds

i rode it about 44 miles yesterday.  it fouled a plug around 20 miles.  it was at a deep stream crossing.  i think the sudden engine cooling had something to do with it, but I've read about other kx's fouling plugs too.
pics after I clean it up.

[MyckMcClung]

jetting specs straight from FMF

"We developed these specs with a 32:1 fuel to oil mixing ratio of a 50/50 mix of race fuel and super unleaded, 0 - 1500 ft altitude at 70 degrees outside temperature."
Jetting Results

    Main  Jet    Pilot Jet  Needle        Needle Position   Power Jet    Air Screw
    
       165        55           STOCK         3RD                    STOCK        1.5
    
Sounds like you are rich, check your jetting specs the way it currently is and report back.

Also if it's still on the stock bottom end, the fouling problem could very well be from worn/leaky crank seals.

[ford832]

Race fuel alters your jetting specs.I don't think I'd use those specs exactly unless you were running the same blend.

[MyckMcClung]

I use their specs with 93, and it is spot on. Of course the temperature it almost always a tad hotter here and definitely more humid than So-Cal.
I posted this with the intention of using it as a starting point.
for his altitude it's probably right on the money, with a fine tweak of the air screw, with pump gas.

[socalcajun]

I myself being the proud owner of an 02 KX250 can tell you this right off the bat. Dump those damn Iridium plugs.  Had nothing but problems with them no matter what my jetting or mix was.  I run BR8EGs with stock jetting and a 32 to 1 mix. Nary a problem.  Be wary of the crank seals. I blew mine while back and you definietly have to split the cases to repair them. 

[ford832]

I've never heard of anyone being a proud KX owner 
It's funny you mentioned the iridium plugs.I've always stuck with my old faithful NGK's-if it works etc,etc. but I've always heard people rave about the iridiums.What didn't you like about them?

[MyckMcClung]

the $38 price tag for one thing.
I run the equivelent  of the BR8es but it's shorter to clear the O/S tank.

[TMKIWI]

I run Iridium plugs.
Change it once a year.

But my bike is jetted properly.

[socalcajun]

I've never heard of anyone being a proud KX owner 
It's funny you mentioned the iridium plugs.I've always stuck with my old faithful NGK's-if it works etc,etc. but I've always heard people rave about the iridiums.What didn't you like about them?
[/quot

The KX is the only bike in the garage at the moment. Check back next week. I may just be a proud ATK owner.   

[socalcajun]

I run Iridium plugs.
Change it once a year.

But my bike is jetted properly.

I hear ya Kiwi. I spent an entire ride day once just playing with the jets and couldn't get it not to easily fouls those iridium SOBs.  I went back to full factory jet specs. and it worked better but not at the price tag Myck mentioned.   

[MyckMcClung]

 when I bought the bike new in 07 I also purchased an IMS 3 gallon tank, I changed the iridium plug to the shorter BR8es(c?) and it was that same plug I replaced Just recently at my rebuild.