I hope I'm not recommending 2.5 out, near sea level, with the stock #35 pilot jet. 2.5 out on a performance modded KLX250, near sea level, is almost always too lean and produces decel popping.. I know about this from personal experience with my bike as well as from helping members, like yourself, solve popping problems.

The next move for the decel pops is a #40 pilot jet. I know of no way, nor have I ever heard/read of, the KLX decel pop through a well tuned #40 pilot. It can likely go rich enough to correct decel pops even through leaky exhaust connections and/or leaking carb components.

As of right now, there is no documented fix for midrange bogging/stuttering except for Neonarc's thread on the Butterfly Shaft Seal - which is certainly an item to check, but new shaft seals has not cured other members' stuttering.

Members have replaced thier CVK's to solve the problem - most recently Josh128..

As with your situation, sometimes simple disassembly/reassembly/reinstallation causes big differences in the symptoms - which point to aberrant carb behavior due to "user error" during its' handling .. BUT this is still very much a mystery and spans almost all model years.


At the risk of sounding like a broken record - this is a malfunction, not a tuning issue. I ran my bike with a DJ150 main jet for quite some time - AFR's dipping all the way to 10:1 (horrible richness) with no bogging/stuttering at all..

 

As far as "living with it" , it's your choice.. This is a significant malfunction. Any and all information you can accumulate from your bike could be helpful. I am hopeful that someone will find a choke plunger that leaks fuel/air/AF at high vacuum ops, or a slide issue that causes aberrant slide behavior during high vacuum ops.. That is the one common denominator - stuttering/bogging during the ramp-up of max TRQ production (around 5K).

 

Going from 2.5 to 3.5 turns made a huge difference with the bogging. Would another bit out help or am I at the max?

 

Well, your at max, but lets talk about you thinking the "3.5 out" affected your 5000-5500 bog.

The pilot system is not capable of affecting, in any meaningful way, the AFR while running at WOT . On the other hand, dis and re assembly of the CVK has produced differences in the stuttering/bogging - which points to a malfunction that gets "better" or "worse" after being handled during a carb session.. Isn't your lessening of the issue due to you having "handled" the part(s) that are malfunctioning?

If the fuel screw can affect this issue, then going back to 2.5 out will make the issue worse?

 

Please remember that when I started this process I admitted I has no idea of what I was doing and I was relying on your expertise to get the most power out of my bike with a slip on and lidless. So I'm not sure what 3.5 versus 2.5 is or isn't fixing with my bogging issue (if anything). I understand it lets more fuel in, but I have no idea of what the magic number of turns is

I can say that maybe I did a better job putting the carb back together the final time, even though it seemed simple enough and I don't think I did anything different. But there seems to be many examples of this exact thing happening to others, so I believe there is merit in your statement.

Klxster, thanks for your help on this. You are a wealth of information

 

I understand.. This bogging/stuttering thing is starting to crop-up more and more and we need a definitive solution other than replacing the carb. Since it seems to be aberrant slide behavior, it's easy to say "well you didn't get the diaphragm/slide spring seated correctly", but no one has actually gotten any further, toward a solution, than recognizing the symptoms change or go away after a dis/re assembly.

Maybe if you spend some time reading this thread and thinking about your carb "sessions" something will "click"...? https://www.kawasakiforums.com/forum...s-fixes-43146/

 

I have noticed the sheen on the slide is gone where it contacts the carb body on my 09. I wonder if a person could rub graphite in to the plastic. The slide looks porous where contact is made. Some of it might stay even with gas fumes and all.

 

Are you having a midrange bogging/stuttering Jct842 ?

 

Kevin, you said you found a DJ washer on the bench... Any chance you only had 1 installed instead of the required 2 when the bike was bogging badly?

Also, do you now have both washers sitting on top of the clip ?

 

Not yet! When I had it all apart I could see how the polish is gone where there is contact though. I have a bit over 7000 miles on the 09.