Hard Starting 2002 KX250

[CylinderStay]

My '02 KX250 is a @&"#$% to start cold unless it has a brand new plug in it. Lets say a new plug is installed, I ride for a day then put the bike up for a week. The next time I try to start it, it will come to life for a moment, then die. If I change the plug, it will start right away. Otherwise, I can kick till my leg looks like Popeye's arm and it will not start. When I pull the plug it will be fouled. Last season I reworked the jetting as follows: -1 size on the main, -1 size in the needle, clip in the second position, -2 on the pilot. This was to smooth out a bad case of sputtering with the factory settings. The only other mod is a 13oz flywheel weight.

Once it's running and warm, you better hang on. But when it's cold and does not have a fresh plug, it's a real booger.

Calling all KX Technicians!!!

Dan

 

[bscottr]

CS,
When did you re-jet and what was the temperature as compared your current temperatures? I suspect that it’s much cooler in Michigan now than when you last changed the jetting. If so, put your stock pilot and needle back in to see if your bike is lean. Two sizes lower on the pilot is significant for cool to cold weather.

Good Luck.

 

[CylinderStay]

I haven't tried starting the bike this year. This problem has existed since I brought the bike home from the dealer last april. So whatever the temp., it's tough to start. BTW, it was WAY rich form the dealer. Spooge and sputtering! The jetting changes seemed to fix it though.

Could there be a timing issue? I'm trying to avoid a service bill if there is a obvious fix, but I might have to take it back to the dealer...

 

[turboandy]

Have you checked to see if the needle or petcock are leaking ? Sounds to me like fuel is getting in the bottom end and fouling the plugs. Next time before you park the bike for a couple of days disconect the fuel line and leave it off until you are ready to start the bike. Just a thought.

 

[Hucker]

Haven't had a single prob with my buddy's '02 KX that has been in the shed all winter. I usually start it up once a week or so, just to make sure everything stays lubed. I noticed the pilot was a bit lean as it "niin niiin niiiiin" when it first starts up, but after about 5 seconds or so calms down and idles. I'd look at richening up that pilot cause with the colder temps, it going to lean it out in a bad way...

(oh yeah, 2 kicks in -25 degree weather :) )

 

[Steve47]

Check you reeds!!!

Chipped reed will do exactly that. The KX are hard on reeds. Then when the bike is cold, it's very hard to start. (Too much fuel gets in the cylinder and you gessed it... foul the plug!)

 

[DWreck]

I have had the same problem with my 98. At first I thought it might be the float level, but I have had it checked. Since I have started turning off the fuel and either riding around a little or leaning the bike over to drain the fuel out of the carb I have almost stopped this from happening. I am still maybe a little rich at idle and have a smaller pilot jet ordered. Steve47 might be onto something there. I am due for a top end and reeds.

 

[CylinderStay]

Thanks all for the good replies. The reeds are one thing I did not think of. Hmmm, maybe while I have it apart... a nice set of V-Force reeds sure would look nice! :-)

 

[Steve47]

Yep, also the 2002 could really benefit from a set of V-Force.

The motor was not as strong as the other years.

I rode 98, 00, 01, 02 and 03. The 2002 had the shortest powerband so the V-Force will help you quite a bit.

Good luck.