So i did the MCM mod with locking the compression realese in the outer position and the bike starts nice (i cranked it over with a wrench on the flywheel and then with the starter before i started it) it started great maybe better than normally but riding it around there is a terrible mid range misfire or something, it runs like crap in the midrange but once you get past the crappy part it pulls nicely.

Live at sea level
pilot jet at #32 trying to find a #40
Main jet at #128
needle ? seems to have a odd profile not a straight taper.

This mod may have highlighted an issue I had already had just posting this for opinions or help, other wise the bike ran better with a nice power surge at the higher end before the mod hence the needle taper.

 

I assume you pulled the spring off the KACR ? If not then you'll have to go back in and do that - Otherwise, enjoy being stranded with a bike that won't start when hot.

Every chance you get, strive to avoid sticking coat hangars (etc etc) inside your engine.

You seem to have the dreaded CVK stumble. At this point in time, it seems that some CVK's have a problematic diaphragm (in addition to a problematic owner). This is a very bad combo, lol..

Seriously, some diaphragms will not seat and seal properly without extra precautions and care during reassembly. Some diaphragm caps may be bent and not seal properly. Also, any slide stiction must be eliminated. You will be dis and re assembling your carb until the diaphragm is seated/sealed correctly. The resources and knowledge you need are in here. See my link below https://www.kawasakiforums.com/forum...s-fixes-43146/..

 

No coat hangers in my bike a nice stainless spoke for me.
Ill be taking the carb apart today hopefully. I wasn't expecting any carb issues with this mod since I rode it earlier that day.
Thanks for the link some reading for the morning.

 

The slide looked good and goes up and down smoothly after reassembly. I just read the 16 pages of this thread (Mid Range Sputter / Misfire - Input welcome) seams I'm not the only one with this issue. Thinking of undoing the MCM mod to see if it goes back to normal.

 

You should understand that the MCM cannot cause midrange stumbles. It certainly will exacerbate any existing carb issues because it increases vacuum signaling and gradients throughout the carb.. Blaming the MCM, and various other things, for the "stumbles" has happened before and will happen again..

There are only a few members that could not get their CVK to work properly after a rejet session - Kshanks5 and a few others, have posted the issue solved with a careful tear down, inspection, and re-assembly.

So you are not the only one to experience the "stumbles". If you can't fix it, however, out of all of us, you will be the 4th member to not be able to do so. Don't be #4..

 

I dunno much but a 128 main sounds lean especially with any power mods in the mix. How does the spark plug look? It can tell you a lot. I took the springs off my KACR. Seemed safer than adding something that could fall apart and destroy the engine: fatigue failure would be my worry since the load on your bent bike spoke will vary and the cycles will be high.

 

Those are the jet sizes I found in the carb when I first took it apart. I did find a #40 pilot jet as I am at sea level. The needle is an odd shape steady taper until about 3/4 from the clip end then a sharp reduction in size to a smaller taper again. Not sure about the plug ill take it out and have a look.
I just checked the carb again and all is clean in there. I found a #40 pilot jet and put that in there, what size main jet would you suggest Im running stock exhaust enlarged hole in airbox lid.
Thanks for the replies.

 

Sounds like you have a DN0352 needle from a DJ2206 kit. Which means you could also have a drilled slide lift hole/port.

You'll need the DJ128 main jet, best clip setting is probably 2N...

 

Finally got to playing with the bike again. In the end I undid the MCM mod to confirm the problem was not that and it wasn't. The bike seemed to have a less noticeable mid range 4000-5000 misfire or stumble once past it it was fine. It turns out the carb settings where way to rich with the needle clip in the forth slot on the needle I adjusted it one slot at a time and it improved and I stopped at the second slot(thanks Klxster) and the flat spot seems like its gone now. I may try the mod again when I check the valves next but for now I just want to ride and not take the tank off again for a while I think I was up to 9 or 10 times.

 

Hopefully I will remember this thread - as an example - the next time I have to warn a member that the MCM cannot cause such malfunctions, but will exacerbate them..

4n with the DNO352 needle is unusable on any KLX.. With lidless airbox, performance exhausts, and proper main jets (DJ140 w stock header, DJ144 with full exhaust system, near sea level) we have found 1N (non-MCM) and 2N(MCM) to be the best. Also, only the stock slide spring should be used in such applications..