Well, I have no data to guide you on setups with the lid on. You see, removing the lid is actually a radical mod - and it's taking a lot of dyno time to figure out how to setup for its' removal.. Just about every component goes "outta whack" on the carb once the lid is removed.. I won't bore you with the details..

You are working within DJ's design parameters of the 2152 kit. As long as you keep the lid, I think you should stay with small to very small tweaks on standard Stage II - IMHO. This means stock Pilot Jet and 3N.. BTW, I believe you are suppose to be running your fuel screw at 3 turns out..

I'm kinda surprised that 132/4N does not carb cleanly - my charts show that even when "waay" too rich, it carbs cleanly.. I'm almost convinced your carb wrenching went "off and wrong"... Remember that in general, a lean problem gets better as the engine warms up - a rich problem is just the opposite.. It certainly seems like your airbox boot is simply unseated around the back side of the carb bell... Even if you counted notches from the bottom and actually are at 2N, I'd think it'd be running well..


Since the MCM does not require a different carb setup to do its' magic, I'd say go back to standard Stage II. The bike will run perfectly well - And it'll have mopowah ... If it doesn't, then you have created a problem during your "wrenching" that you'll have to find and fix...

I have no data-backed advice for a setup as I have no data with lid on - In general, the MCM is "unleashed" when you feed it more fuel over the entire RPM range compared to standard stage ll. I guess if I were you, after riding and getting to know the bike with standard stage ll , I'd drop in the 132 .. DJ put it in the kit for a reason - perhaps because the 128 can be lean near sea level.. Just FYI, going to the 132 (with 3N of course) will fatten (richen) the AFR everywhere except idle..

 

Snowdrifter, If you order jets, and you think you'll, someday, setup with lid off (even just to compare power.) , I don't think you'll need to get anything larger than the DJ140. You certainly could get 134, 136, 138, 140 and have all your bases covered, lidless or not..
Someday, you could ride all morn, switch to 140/3N, lidless, w/o butt plug, and ride all afternoon.. Bet you never go back..

 

Honestly you are at the same elevation as me. I was hesitant to try the 140 main. I really thought it would be too rich. But I must tell you, unless you have your clip on the 2nd slot from the top, you may never like the midrange. So far this is my best setup since doing the cam mod. Just pull your snorkel and try. I like the KDX snorkel because it's quieter.
Also the bike pulls through to 9k rpm whereas with the 132 it cut off sharp at 8200rpm.

 

FWIW, because I don't have any dyno sheets or equipment to get ultra precise, I just have old school seat of the pants experience. Clearly that isn't as good as dyno or instrumentation, but it's all I had.

KLX250 with stock pipe, KDX snorkel in lid, MCM, I did the following:

16009-1912 Kawi Needle-Jet, N1TC
92037-1401 Kawi Clamp, Jet Needle
92143-1667 Kawi Collar
Needle clip slot 2 down from the top
92063-1069 Kawi Main Jet #125 or 92063-1074 Kawi Main Jet #128
92064-1108 pilot jet #40 Air screw at 2 turns out to start
drill the slide vent to 7/64ths

I don't remember for sure, but I think I did the 125 main. Before that I had tried just the drilling of the slide, the pilot, and shimmed the needle about .030". The bike had what felt like a miss at 6000 rpm constant throttle. I pulled the choke (enrichener) and it would go away - lean. So I finished out with the needle and its bits to fit it, also going 2 slots down. My brother had done this on his KLX and it worked fair. I had given him a Dial-A-Jet I had for my SR500, he said it smoothed out the glitches in the carburetion, so there were lean spots within the circuits. I did the same.

The bike pulls strong considering it is running a 15/39 sprocket where you don't hit sixth until about 55 mph. Pulls fairly strong.

I only tell you this to say consider the Dial-A-Jet since it is a dynamic fuel adder - adding "on demand". Kind of a fuel injector like the Mikuni power jet. I don't know the science behind it, but do understand it works through flow dynamics (which I do understand to an extent) and acoustic wave patterns in the intake (which I do not understand). I have been using the product for the past 25+years in my street bike at one time and my KLX650. With the carburetion set up to the lean side as the instructions point out, the Dial-A-Jet works a bit all the time and gives more range for altitude change.

But suffice it to say it worked in both my KLX650 and 250, and my brother's KLX250. Oh, we're around 900 ft elevation, I've ridden the 650 from 0-5000 feet without any noticeable change in performance and no hard jetting.

I used this calculator to do a bit of educated guessing on exhaust head pipe length and size. I used the specs I had available from earlier 250 timing at 61 BBDC with change for the retarding and figured 8600 rpm based on Kawasaki's peak. Comes up with an ID a bit over 1-5/16".

 

The possibility of a large power increase is tempting, but I also place a lot of value in keeping the bike relatively quiet. Thus why I kept the lid and installed a smaller exhaust outlet. That being said, it's my understanding that the MCM is effective at quieting the intake noise, so it may be possible to lose the lid now. Might have to try it and see how it sounds. However, per your other posts, removing the lid is actually a drastic change and will require larger jetting. Something to think about.

As a follow up to my previous post, I went back through and checked the carb boots and clamps, sprayed starting fluid around the joints, and everything checks out OK, no air leaks detected. Set the fuel screw at an even 3 turns. Logged a few more miles and was able to narrow the worst spot down to 4.5K - 5.5K RPM at full throttle. It bucks and chugs and struggles to gain speed, but then cleans up at about 6K RPM. Below that is OK, not particularly strong, but not choppy. And above 6K seems to have more power than pre-MCM. Tried pulling the choke (enrichener) at the point it was struggling most with, and it had zero detectable effect.

That now has me wondering if it's actually on the rich side? Given that the top end seems pretty good, is it simply that going from 3N to 4N, and from 128 to 132, is enough to cause that? Haven't had a chance to experiment yet. Thanks to all in this thread, there's a wealth of information here, just have to interpret and make sense of it all.

 

Snowdrifter, I don't pretend to be a troubleshooter - so I'm thinking out loud here..

4.5-5.5K @ WOT is where the needle/slide are opening and fueling the bike.
6K @WOT is where the needle/slide are open and the bike is beginning to fuel off the main jet.
Your issues seem to be with slide/needle operations.
Assuming your choke mechanism is functioning correctly, it having no effect would suggest the bike is already seeing some kind of huge fuel dump. I can tell you it will take a horrible dump of fuel to create that kind of problem as my testing went all the way down to 10:1 AFR in that range with the DJ150 with no carb'ing issues at all.

Hopefully, it is just an issue of being at 132/4N with the lid on. Perhaps pull the lid for a test. My data and experience indicates 132/4N will run just fine, but be lean everywhere. Perhaps with your soda-straw insert, it would be richer, and have a more proper AFR, than my bike..

 

ianmcdca, until now, I haven't read about your results of running a "generic" 140 main jet with 2N and a KDX snorkel.. I know your carb kit is not a DJ kit,(Moose?) so your needle/spring/etc are not known to me - Also, I don't know what exhaust your running - it's not in your signature line..

Assuming your running at least an aftermarket silencer, what happens when you pull your lid? I would guess several additional HP above 7K..

 

For what it's worth, I'm running lidless with the stock exhaust and a DJ124 and the needle at 4N.

It's lean up top past 6k (to be expected), and too rich down low below 4.5k rpm. If I go to 3N, its too lean in the mid range and top end = no power. It's fine on the street with good response in this configuration, but off road if you get on a hill it bogs really quick.

Should be all fixed this weekend once I throw on the Q4 and rejet to #40, 3N DJ138 - thanks for KLXsters documentation

 

Pwjm, did you get a selection of jets? DJ jets? Reason I ask is because a 140 at my altitude is apparently equivalent to 137.2 at your 2K.. And your Q4 may not flow as freely as my DGR, which, if so, would not use quite as big a jet as my bike.. IMHO, You should certainly try 138/3N first, but with a "chance" that 2N may work better with the 138.. Your gonna want your top end fueled well to get the "Raped Ape" power up there.. This'll be power you've never felt before..

 

Picking up the jets today. Ordered a 136 and a 138.

I have a hard time believe the slip-on's would different enough between brands to justify jumping a whole main jet range. On a dyno it might show, but not every day riding.

>This'll be power you've never felt before..

My body is ready. lol.

Question for you... your wheelie videos, what sprocket config are you using?