I'll try DJ 140 aka k152, just for you KLXster :P

I had a few hours yesterday to muck with the bike. I should have mentioned that during the stage II install I spent extra time cleaning the carb. I had a weird buildup of something red (don't know what) under the lip of the diaphragm where it seats in the top of the carb. I should have take a picture. There was also a hard substance on the surface of the "lid" where the "spring tabs" are. It wasn't flaking off but when I tried to remove it, the stuff came off in flakes. None of my jets were plugged, but I used guitar wire just to be sure. I verify slide operation after every install with my shop vacuum.

Lastly, I left the "tps" sensor unplugged. Maybe a combination of cleaning and the TPS sensor that "does nothing" cleaned up the mystery hesitation when engine is dead cold.

To be fair to everyone and myself, I've reinstalled the lidless recipe. I'll take it for a spin today to see if the trouble I was having has been cleaned up. WIth stage II, I can rev it to 4k and snap the throttle and pull the bars, getting front wheel lift. If I can repeat this with the lidless recipe, I'll leave it installed until the slightly smaller main jet arrives.

As for noise, maybe it is just the pipe growling louder... either way it is a bit annoying and I like the bike a bit quieter. I have to decided what is more important... power or noise... power can be had with less noise but that requires more displacement. I know that the gains made with the lidless recipe are great for someone who just paid top dollar for their KLX250s and doesn't want to drop another 1000 on it.... but I bought mine for 2500 bucks. Spending another grand to get it running with bikes that would cost twice that much isn't a big deal.

 

With Full FMF exhaust, the starting RPM for a snap-to-wheelie increases (Over the 4-4.2k when using the stock header or, apparently, DJ Stage II + Snorkel on a Full Exhaust+MCM.) I can't remember the exact number.. My bike is out at the Ranch..

Once you find the new/correct starting RPM, it's "Wheelie City".. But this may not "fit in" with your preferred riding style/expectations..

If there is/was a driveability issue with the lidless setup, we should attempt troubleshooting.. E.G. If you are really running a #35 pilot with idle set to 1300 RPM, near sea level, you are quite lean during all Pilot system fueling operations..


The DJ140/K152 @ 1N with stock spring and lift port is the recipe for near sea level + stock header + lidless airbox.. It's Dyno and DynoButt's proven.. With MCM, 2N is an option for a slightly "fatter" low to mid range..
My vid below (signature line) shows the "wheelie results" of this recipe - with stock spraughKets, you snap from about 12-13 mph indicated..

 

Don't worry ditch pickle. Some bikes are different and some riding requires different throttle inputs for best overall results and RAD in areas is different too.

I've got a Canadian '07 and it is different too. It has many differences in the carb hard parts and maybe different body too. Needle jet is different (part number), emulsion tube is different (less upper holes) and stock needle is different (NFKT). My (2 different carbs '06 and '07 CDN) carb has 4 holes pre-throttle valve as well as the metered hole after the valve (I've read 3 pre-valve on this site from some but could be wrong but I looked hard to find why my bike is different).
My bike will 4 stroke rich a 9000rpm with a K140 (1500' testing) and almost die at 7000 rpm with a K148 (all lidless). 128DJ is closest but a bit rich for summer heat.
With stock needle (091" root diameter) it is too rich from the get go with these larger jets at low slide positions and lean in the mid then rich on the top. Shimming just moves this up and down predictably.
With DJ 300 needle (093" root) a 1N it is lean everywhere and 4N is pukeing rich everywhere. At 3N the bike will wheely from corner to corner like a little 125mx if you work it from 5000 to 8000r's then fall on it's face below. At 2N it's better at 4500r's but less above. At 1N a stock '09 is better everywhere.
Heck, the second taper isn't even out of the reduction (the fuel metering part before the larger diameter, taller choke) in the needle jet at 1N on mine. This needle position barely requires a main jet. Try it, I did.

Any how, this "proven" set up don't work for me either so don't be afraid to do what is best for you.

Same with the MCM (on my bike anyway). I've done and un-done it twice now with many jetting rounds and combinations. MCMing makes it very picky to just get close on engine management especially with an open air box.
My riding buddy with a stock '09 (except for suspension, gearing and tires) is my standard. We switch up on bikes during our rides, once in a while, to compare. MCM adds to the 5000 to 8000 range and takes away from below that and above. What that does is lose you your rpm spread forcing more gear changes throughout the ride. Every gear change is a small loss in time in a 4 hr ride which means slower.
I guess it is how you evaluate "performance". A wheely at a particular rpm or quickest time through the trees and trails of the day.

Nothing for nothing in this world. If you ride goat paths from 1500' to 6000', predictable and wide spread of power will give you better performance than dyno indicated peaks every time. 1 or 2 ponies extra in one area a means nothing if you're above or below it because of the gear and incline (load).
And,,, flat land and dyno tuning will never replicate the changing full loading of a little 20 hp motor lugging 500 lbs of mass up a switchback goat path from 2500 to 10,000 rpm.

So ditch pickle I'm with you. Make it what you need in your reality cause that's what counts eh.

 

Fascinating, having different internal parts and a different pilot system could explain a lot.. I worked with a Canadian for over a month trying to get his carb/fueling correct - we never could - and it's possible he also had a "different" CVK34..

Obviously, a different needle jet, and emulsion tube, would produce unknown results from known recipes, regardless of the lift port size and spring choice. (In your case, fewer "standard size" aeration holes would logically mean a richer AFR - And your MAJ may be a different size, throwing everything "off" ..) The extra transition port should not be a big issue..

Your weird MCM results might indicate a different stock cam timing as well.

A dyno test verifies viability and effectiveness of a tune, it's just a tool to make sure you aren't doing something stupid with your choice of setup - then, and only then, can you fine tune with Dynobutt testing. No need to place any more value on Dyno testing than that - I don't..

 

Interesting, as far as I know my SF is Canadian spec and runs perfectly with
#152 kehin main
N1-tc on 1st notch
#40 pilot

 

RHITB. '08 on had the NNLA set-up that is familiar here.

KLXster. 16.5 thou #50 MAJ. Needle jet (choke height and orifice size) are different part numbers between 300, '06 '07 CDN 250s, '08 and on North American 250s as well as emulsion tubes.
I had dynos available to me in he 70's and 80's when I was still in the biz. I used O2 wide band when EFI took over. In the end it was a help but fine tune was still reading plugs and piston and most importantly rider input.
The transition stutter (that I read so much about lol, hint, I had it) is a slight rich condition. More info on harley and scooter forums than you can shake a stick at lol. MCMing amplifies it by adding to the pressure threshhold at which the slide begins to rise. With MCM my slide begins to rise at 2000 to 2200 rpm and at stock timing it starts at 3200 to 3500 (with stock spring, drilled and standard vacuum hole made no difference here).
To prove this to myself after observing it on the bench and to try to cure it, I stretched a stock spring 3/8". This extra preload would hold rpm back a 2000 when applying light throttle on the bench. Not a stall because more throttle plate opening began the lift. With MCM the lift started with about 3/16th's to 1/4 throttle grip twist and with stock timing about 1/4 to 3/8th's twist, same stretched spring.
Interesting enough to me that I looked at my other 2 stock springs and there was an 1/8th" difference in overall length. Maybe overlooked sometimes but spring rate is very important on a slide controlled by it. Little bit makes a difference when you open that box.
To fix the stutter (3 different slides, 2 different cv carb bodies) at transition on MY BIKE with MCM required changing slide cutaway from .5 to 1.5 (approx, 8% more air in the cutaway range) and 1/4" added spring length). This changed the reaction rate in the field from a pop up wheely that ended as soon as it started to 60 to 90 feet of front wheel 1 foot high. Noticable, better control, FELT slower, but it wasn't lol.
Cam timing, who knows eh. Part numbers may be the same on the hard parts but things can change over the years with specs and manufacturer. MCM added spit back a higher rpm (I run dyed fuel off road and it is real easy to see when fuel goes to the wrong spots on a rejet lol) on MY BIKE and took away 1500 rpm (even if it is weak) of powerband up top but the little kick between 5000 and 8000 is fun. I should add I have stock exhaust 1.75 " outlet, stainless screen, with the last plate drilled three more times and spark arrestor left intact (live in wildfire country).

I only joined in because I researched this forum with the desire to make my new to me '07 250s (my plated CRF 450X is too much like cheating when out and about with my senior friends lol) the best it can be lol. I tried, with intense hope, that the easy way was the best way but it didn't work on MY BIKE. So for others out there, every bike is it's own so like mine your's may be different.
In the end MY BIKE works best with close to DJ's recommended lidless 300 set-up and the tweaks I needed to do to fine tune. Hopefully after I install the 300 this afternoon i can drop to clip 4.

On a side note, and speaking of cheating lol, I ordered a Chinese 300 kit (256.95 loonies to my door and 6 days delivery). It's not bad. Look for the one that has 299 stamped on the cylinder.
Piston is lower compression (good cause even the 250 has given me some knocks during testing with our fuel up here) , 8 gr lighter that OEM 300 but pin just about equals it out, same taper, fit is 1.9 thou. Rings good quality with good gap. Barrel casting is a little less finished externally but structurally sound and equal to OEM in dimensions. Machining on base is excellent, head surface has a bit of light milling chatter (probably fine but I lapped it anyway), honing is a little rough looking at it magnified, they should add to coolant flow to help with build up. Steaming hot water and soap wash is needed to get the bits out.
Gaskets are a no go (get OEM, work perfect). Besides fit a bit off, two coolant holes in the head gasket are punched out wrong and would cause an overheat due to restriction. Too bad because the quality and material would of been fine.
All in all a darn good deal for up here.

 

Well, your writing style makes it hard for me to put all the pieces of the puzzle together. But it is clear that you very much had to "reinvent the wheel" in order to get a performance setup, that works well, with the different needle jet, emulsion tube, etc etc..

With one of our Canadian friends, PWJM, he and I could only get his CVK to act properly with what would ordinarily be considered extremely lean setups - like you, a DJ128+Lidless.. I certainly hope your posts have explained why this happened, as otherwise, it is still a complete mystery..

It is a mystery how your MCM produces nearly opposite results from the MCM Dyno charts/MCM Dyno chart comparisons - which show significant increases below 6.5K and slight decreases above..

A KLX is a KLX - they come off an assembly line built with standard parts - attempting to attach attributes like "every bike is its' own" is not warranted as they are not biological. I only say this because such is used to cover up inadequate knowledge, or lack of determination to discover new knowledge - it's always a prelude to "quitter talk".. Sure, buying a used KLX can mean having to launch an expedition in order to find and fix "creative mods" by previous owners - but it is something you sign up for when you buy a used bike..

Apparently we now know that some CVK's are built with different fueling components.


I'm searching for new "rules of the road" out of your posts -

How to know if you have a "Canadian" CVK - A CVk that will not accept known working setups.

1. NFKT stock needle.

2. The emulsion tube will be missing some/all of the upper aeration holes..?

 

I can post pics of the NNLA, the emulsion tube, etc etc.. in order to keep anyone else from having this nightmare.. It is possible this issue has forced at least two members to buy TM36's to get their bikes to run correctly.. Not a bad upgrade, but a forced upgrade..

 

Thanks for all the feedback, here I was thinking I had done something wrong, or had a faulty carb. Way to be different, Canada...

I was also considering the TM36 fix, but now that there is some more reference material I'll keep at the cvk34.

If I'm not mistaken, geo is running the DJ klx300 kit? I'm not trying to tune given your setup just trying to make sure I'm following you correctly.

I have the klx250s DJ kit, and a k158 main jet. I'm wondering if using the stock needle shimmed would provide better fuel metering down low, given my wacky carb.. where it feels too rich using the k158/lidless? Or does the variation of MAJ cause my fueling to be too fat :/ I've got research to do

As for the chinese 300cc jug, I'm very intrigued. I'd be happy to spend 250 canadian for 50 more CC's...

 

Ahh, DP, were you experiencing horrible stuttering in the 5-6K range? I've read your posts and don't recall you talking about any kind of operational issues..

What Geo and PWJM experienced is horrible stuttering and overly rich fueling in the upper half of the RPM range..