I thought I changed all those old posts to reflect latest findings. I'll go through my posts and check.. In my defense, the need of 1N is a relatively new finding.

IIRC, the longer spring is the stock spring. Of course, one of the "old mods" was to cut the stock spring to a shorter length - so if a previous owner cut it...... The stock spring is very close to the DJ. It may take a micrometer to tell which is which..

Going to 146/1N for the 330 kit sounds perfect.

Regular super glue is fine. That area sees only filtered air, no fuel..

 

Its all good Klxster, good news is I am getting fantastic at changing jets/needles, had it swapped to 1N in 10 min flat

Mid range 4-7k is definitely improved, does not sound as "fat/rich", and pulls cleaner in that range. I still think it could be a tad rich in terms of performance, although maybe I am expecting too much from a little 250.

Runs hard all the way to 10K it seemed like, throttle response is perfect. I was able to create a small 1-2 revolution stumble with certain quick on/off throttle at high rpm, but that is probably just a CVK carb limitation not the jetting...

Overall this thing EATS now, definitely feels like a hot 250 with that jetting setup, definite improvement over the DJ Stage 2, thanks for all the suggestions

I do still have some decel popping even with the 38 pilot and about 1.5-2 turns out (forget which I did), but it doesnt really bother me and bike runs excellent otherwise, I was thinking about just leaving the pilot system alone...

 

Great news.. You now have "state of the art" power for your mod list.

I've never previously heard of your "small 1-2 revolution stumble with certain quick on/off throttle at high rpm".. We all know of the "1 stroke ignition miss" that the ground mod usually fixes.. So if your issue IS carb related, there may be a small problem with your CVK..

Decel popping means your fuel screw is too far "in" - and if you are near sea level, 1.5-2 out on a #38 is not correct and certainly should be causing decel pops. With a #40, near sea level, we usually end up right at 2 out. Your 38 would need to be further out than that - It is best to take the time and the possible burnt fingers to set it half way between idle drops - You only have to do it once.. I bet you'll find it's setting ends up closer to 3 out ..

 

For example, if I am WOT about 8k, and close the throttle to 50% and then back to WOT in about 1/4 second (i'm talking real quick), it would miss for a stroke, not really a choke or bog or lag, just heard it more than anything. It's not even worth mentioning bc I was doing everything I could to make the carb "act up" and if that's all it does then I am a happy camper, i was able to get it to do similar on the stock settings btw...

I already have the ground mod done. I will back out my fuel screw and i'm sure that'll fix the popping, I dont really see it as a big issue though. I may be mistaken but didnt i read somewhere that you wanted the fuel screw set towards the lean side anyway?

 

Well, again, optimal is halfway between idle drops.. Once that has been achieved you should not have decel popping and should have great low-mid RPM throttle response. If you wanna micro manage it, then from the halfway point you could go a tiny bit toward lean or rich.. Remember, the fuel screw only controls the AFR at idle and any operations under 1/8th throttle as well as a "little" control over transition to "needle operations" when the throttle is opened past 1/8th.. Now, on the other hand, the pilot jet fully controls the AFR of the "simulated accelerator pump" when you snap or roll the throttle open, through the 3 tiny transition ports. So with your mods (chewing through more air at all times) the bigger pilot gives the "better accell shot".. This accell shot is NOT affected by the fuel screw or its' setting at all..

 

Should i order a 40 pilot then?

 

I also just bought a powerbomb header and have the 330 kit coming soon so... I will be doing a lot of changes haha. But i can offer my calibrated butt dyno reviews...

 

Keep the #38..
If you are going to put on the PowerBomb before BB kit, you'll need to change only one thing- DJ144 instead of the 140.. You'll loose TRQ and throttle response below 6.5k but the power above that ( 7000-10,500 rpm) is quite "eye popping".. With the PBomb, the bike is best ridden at 5K and above without MCM helping the low/mid 's... Obviously, without MCM, the low/mid will once again be a tad rich when simulating a dyno run - but who does that out in the real world anyway..?

 

do you think the megabomb is a better choice? I can always return it...

But ultimately my goal is the 330 kit (going on 6 weeks waiting at this point...) so a minimal loss of tq down low should more than be made up with the 330 kit and high rpm should be enhanced...or at least thats my thinking, and the Pbomb is a good $100 cheaper than the megabomb

 

Understand that I am talking about the ramifications of putting the powerbomb on your 250 .. I'm sure the 330 will make a better TRQ curve with the Powerbomb compared to the stock 250 header..

I assume the Megabomb costs so much more because it is tailor made for the 250. And if so, the 330 would/could defeat all the "goodness" it gives to a 250. Also, we do not know exactly how the Powerbomb and Megabomb compare on the dyno.. Yes, I could actually do this comparison but I have no time for such things these days - heck, I can't find the time to restart my ignition curve project.. It is possible that the differences are not worth the money.. So, IMO, keep the Powerbomb..