First long ride on the 140/1N, i adjusted my 38 pilot to about 2.5 turns out, much less decel popping, still there juuust a tad.

Ran great except for in the morning, it was about 65 out, it comes off choke and idles by itself in about 20 seconds, i let it warm up for about 3 minutes, experienced a lean bog around 2-4k for about the first 2 minutes of riding before it warmed up all the way i guess. Ran perfectly fine after that...

DJ Stage 2 almost never did that (probably bc it was rich as hell midrange), even in the winter, but the stock bike sure did. Bike has always been cold natured until it warms all the way up, just curious if others have experienced the same.

 

Put some good time on the 140/1N the last 2 days, definitely a VERY good rideable setup with excellent characteristics almost everywhere and great throttle response.

One potentially negative thing I can say about 140/1N and my mods is my mid range is soft soft soft.... Something not quite right there I don't think. It may be bc my bottom end and top end are so much better...but it just feels like there's absolutely nothing going on between 3K-4500. Give it gas in that range and tq is just nowhere.... It feels like it pulls better at 2500 than it does at 4k. But after 5k.... Very awesome power, I also cannot explain just how much LOUDER my bike got just changing jets, almost ear bleeding loud even with a Q4. Can't help you on the midrange with that setup bc already moved onto.... powerbomb

 

Just some quick thoughts bc i rode with/without the powerbomb back to back on the 140/1N combo.

#1, i can now power wheelie in 1st gear (never able to do that with any setup before)
#2 huge increase in tq/throttle response below 3500, I did not think the p-bomb would do this.
#3 mid range 3500-5000rpm is maybe the worst it has ever been, lack of tq or any real power in this range...definite dead spot for my bike, not a bog or lag, just a real flat power area with nothing going on.
#4 above 5k rpm... HOLY COW!!!! klxster was right, better hold on, way more top end than i would have imagined, extremely noticeable boost in power back to back, revs faster, pulls a bunch harder...doesnt even feel like the same bike.

Overall, with my mods at least, the P-bomb was the best mod i have done to this bike, 2nd only to changing from stock jetting to DJ stg2 (or others), compared to the stock header, it feels like a different bike.

 

Lack of power below 5K is normal for your current mod list. You'll pick up even more top end power with a DJ144 main jet - you are too lean with DJ140/1N Lidless+Full FMF exhaust for max power 7-10.5K rpm..

Bet you been hitting the rev limiter by accident..

Very useful information/observations - back to back runs with stock header then Pbomb..

And BTW, since you have this recent comparison fresh in your mind, Adding the MCM to your bike right now will give you all the performance you had with the stock header (3K to 6.5K rpm) AND the performance you have now 6.5k - 10.5k..
MCM would "restore" your TRQ, below 6.5k, to your "pre-Pbomb" levels.. Best of both worlds!

Of course, your BB kit will respond to DJ146/DJ148/DJ150 - 1N just as your 250 is now - likely meaning you are about to make freakish power outta that 330 kit..lol

 

Apparently, few are capable of noticing the change in engine sounds when fueling is proper for max power - it was always obvious to me, as it is you..

So, I've gone back into my tuning threads for you.. I calculate that you are losing about 2 hp on your top end with DJ140/1N compared to DJ144/1N. Your current setup should be right at 25 hp, you are likely only seeing 23 right now. Our KLX250's, when fully "uncorked", will require 12.8:1 AFR on top to produce max power - the DJ144 just barely keeps it down to that with a full FMF exhaust system near sea level.

 

Does anyone know off hand what the original diameter of the slide hole is? When I installed my jet kit I followed the instructions and opened it up with the 7/64s drill. This was obviously before I found your recipes Klxster.

I have a DJ140, 142, & 144 jets coming and was going to fill the hole with some JB weld and re-drill it to the original size. I just haven't been able to find the original hole diameter anywhere.

 

Use a 3/32 bit to redrill. Avoid drilling "wobble" while drilling, and the port will be restored.

The stock port seems to be .1" or 2.58 mm. So with careful drilling, 3/32 gets it done..

 

Here we go! one more jumps in..

I just got a stock-engine '09 250S and for the first stage of tinkering will be prepping it for frozen lake riding this winter. I'll be at ~800 ft above sea and anywhere from 0-40 degrees Fahrenheit. My major goal is good low-mid torque to move 200 lbs of me and gear plus some heavy studded tires.

I'm going to try futzing with the carb only for now. I thought I had my head straight after reading a bunch of klxster's posts, but now I'm kinda unsure. I ordered a DJ2152, but after arriving at the end of this thread I'm wondering if the DJ132 is going to be enough main. Plus, I might ned to get a #40 pilot. Guess I'll run a stock/snorkel remove box for now.

Thanks for all who contributed to this thread. Lots of great info here. I'll see if I can get decent results with a DJ stage 2.

 

Until you fit a performance slipon or entire performance exhaust system onto your bike, you are limited to using the standard DJ stage 1 or 2 as per the instructions..

However, you will need to do the MCM - and you need to do it yesterday..!

 

Yes, the MCM will be done. I think the path I'm going to take will be DJ stage 2 first to start, then slowly migrate to what you're running. MCM + full exhaust + Lidless + more jetting work to get the CVK to work well with that.

Next year I'm already thinking 351 and a pumper if I'm not satisfied with the 250 optimization. Good news is that my perception of speed and performance is modest.