yes, elevation is well below 500 ft, closer to ASL

the shims i am using are basically washers, there was also a plastic one that came with the kit. i have 2 on there now and i have one more i could put on, pictures attached.

being that i'm located so close to ASL, should i look to shim this even further than the 2 currently on the needle? what issues am i looking at with an "under shimmed" needle running the 158 main jet + lidless+exhuast, still a lean condition? if i'm understanding correctly the shims are effectively bringing the needle up, allowing more fuel to flow.

the instructions on my kit compare one shim as equal to 1/2 clip position.

 

The thickness you are looking for is two of those metal washers worth.. This should insure good throttle response and power ramping from low RPM's - and good gas mileage if you are into that.. If you like to work on your bike, tuning work that is, you can play with increasing the shim pack a little at a time, over time..

I know you are grabbing at tidbits of knowledge and trying to make determinations - and that's fine, it's normal to do so.. But for now, you are going to need to use our knowledge to get you running well. If you want to become a CVK/KLX tuner, we can talk on PM..

Here are your two options:
K158 +.040" Shimmed NNLA+Lidless+Pbomb+TBR
K152+.080" Shimmed NNLA+Lidless+Stock Header+TBR

Otherwise, for running with the lid on, you'll need a DJ kit or jets+N1TC.

 

i started it up last night and did a quick spin with basically the ebay jet kit installed per instructions (2 shims on needle, the mystery 135 main jet, 40 pilot and A/F screw 3 turns out). PB/TBR slip on and lid w/KDX snorkel.

i will still be moving forward with the other bits advised (larger main and needle) before taking the lid off but have to say it ran SO much better than before, i must have been really running lean much smoother, nice settled idle, snappy throttle, no dead spots/surging, no backfire/popping off coming off throttle.

can't wait to see the next level!

 

Going Lidless+PB+TBR+ K158/DJ144 will produce a far more powerful power curve above 6.5K rpm with perhaps a softening of power below that, compared to what you have now..

 

had my first real ride with the Lidless+PB+TBR+ K158 combo (along with the 13t sprocket) and love it!! such a different bike. i do have the N1TC as well that i'm going to put in.

still not pulling wheelies though

thanks for everyones patience and help, especially you Klxster!

when installing the N1TC, should i go to clip position 2 or 3 running the 158 MJ? also- the spacer sits above the clip, correct?

 

Without MCM, I do not recommend the N1TC for your bike. You are running a "top end power" mod combo at this point - so fueling needs below 7K are very "relaxed" with your bike. As you can see, even the stock needle (shimmed) produces good performance below 7K with your current mods..

N1TC, with its' short length and relatively aggressive fueling tapers, will tend to overfuel your bike below 7K with aggressive throttle settings/WOT..

If you must, only use the top notch (1N) , and be wary of a possible softening of power below 7K with aggressive throttle positions..

Spacer sets above the clip.

Your bike produces the bulk of its' power above 7K rpm now - wheelies will require a higher starting RPM in order to hit the peak TRQ when the throttle is nailed wide open.. Done right, and with the 13T, you should have a wheelie monster at this point..

 

N1-TC was among the jetting changes done by the earlier KLX riders when they came out again in 2006. D. Pippen among others has it as the way to deal with the mid range, running in the second notch.

 

Got it... I attribute my lack of wheelies to user error, still kind of a newb rider. I've popped a couple "oh sh#t" wheelies with some rolling clutch dumps on the throttle just not planned ones. I'll wait on the N1TC for the cam mod down the road.

It feels pretty much as you describe, a little softer in low rpm but the 13t helps that- still torky in the 3500-6500 range with power building beyond that. I road pretty hard on trails yesterday and spent most of my time around 4500-7500 rpm, felt like the best balance of torque and power.

As an FYI it definitely is idling smoother with the larger main and lidless... Not sure why since that should just be the pilot but it's very noticeable... I had a hard time getting it to settle under 1500 rpm before and it actually died a few times coming to a stop with the clutch in. Now it's great sitting at 1200-1300.