All right guys I did the carb mods and well I'm a bit dissappointed. My bike is at 676km.

What I did:

1. 125 main jet
2. KDX snorkel
3. #40 pilot jet
4. .032" shim on needle (waiting for backordered KLX300 needle and coloar)
5. 2.5 turn out on air pilot screw

Previous mods:

1. remove stock snorkel
2. cut and drilled exhaust system to 3/4" hole throughout pipe.
3. 3/8" crank case vent hole

Performance before carb mods:

Idled perfectly, no hesistation off the start. Pulled pretty good to about 8000rpm and that was it. Was running lean indicated by the spark plug.

Performance after carb mods:

Idles a little eractically. Very slight hesistation off the start. pulls good too about 7000rpm. Will go to 9000rpm but after 7000 bike trembles a bit. Throttle response feels slighlty better, and there is more torque foresure. The bike also run about 50'F cooler than before.

I was expecting better high rpm performance. Is getting to the red line smoothly a dream? Do I need to adjust the pilot screw to fix idle etc? I'm thinking of removing the KDX snorkel and seeing the difference.

Whats up???

 

just pulled the spark plug and it was totally black! Way too rich. What should I do?

 

Hey Greenmachine,

I'm not sure what you mean by" My bike is at 676km". I'm guessing that you're at 676 meters elevation? Which equals about 2,200 feet for Americans ( are we ever going to switch to metric?) Anyone else at 2,000 ft or so? If so, what's your set-up?

 

i would think 2.5 turns out might be a little much with a 40 pilot. turning in .5 a turn to 2 turns out and see what happens. mine is stock 35 pilot 2.5 turns out

 

sully i think he means his bike has 676 kilometers on the speedo

 

B I N G O !

 

Marty, KLXstiffler, do you guys think the 40pilot is necessary or even do any good for that matter?

 

I don't think the #40 pilot is necessary myself. 2.5 turns out on the stocker has the bike running better than any carb bike I've ever owned.

 

Well after much thinking last night I came up with a strategy to fix the carb jetting problem temporarily with no new parts.

1. I turned the pilot screw out 1.5 turns. Idle was better and no more hesitation when hitting the throttle. The spark plug was very slightly brown with black around the edge. It looked a little lean. I also noticed that the poping was back on deceleration. (I had to take the starter out to play with the pilot screw, but better than removing the carb)

2. Next I left the pilot screw at 1.5 turns out and removed the KDX snorkel. Idle was good, definetely less jump when cracking the throttle, but the bike pulled wide open all the way to 9500rpm without any trembling. The plug was lighter than step 1.

The issue to me seems my how I adjust the pilot jet down low and air flow for wide open throttle.

Option 1: Use the KDX snorkel, stock air filter, 122 main jet
Option 2: Use no snorkel, stock air filter, 125 main jet
Option 3: Use KDX snorkel, higher flow air filter, 125 main jet

Conclusion:

I will set the pilot screw at 2.0 turns out. This should give me the right mix and performance when cracking the throttle. Also the poping should stop. With the 125 main jet in I will use no snorkel unless I change the mainjet size or air filter.
It is a shame not to use the $35 KDX snorkel. It is interesting how even though everybody in this forum has the same bike and often the same mods, personal fine tuning adjustments need to be made to make your own machine run perfectly.