Concerning DJ132/4N + Full FMF system:

While the AFR below 7k is acceptable, the AFR above 7K is not.
Above 7k it ranged from 13.5:1 to nearly 14:1 which cost about 3hp - A 3hp loss compared to DJ144/1N..

Our KLX250's like/want/need a low/mid of 13-13.5 with a top end of 12.5-12.8 for max power and throttle response throughout the RPM range.. Getting this is practically impossible with the needle choices available to us at this point. All we can do is go 1N, stock spring, stock slide lift hole.. The DNO352 needle in the DJ2206 kit is a good bit leaner in the low/mid than the DNO228 needle in the DJ2152 kit, but has too much taper near its' end. So 1N etc etc is still called for..

 

I appreciate you wanting the most power avaialbe from the stock bore and cvk34, but "acceptable" is a subjective term. I'm not blaming anyone but myself for my misconceptions, but I interpreted acceptable as safe. With the dyno chart results you have posted, one could safely run a 132 main jet with a lidless setup, something I didnt realize beforehand. This is all I'm pointing out, not wether or not those power levels are acceptable to you, or anyone else for that matter when compared to the gains made with DJ144/1N or k158/1N.

Your entire perspective is from the point of view that more can be had, and that's ok. Im even willing to try it myself.. but I would perpersonally like to see more power down low/midrange than at the top end. Again, one person's level of acceptable vs someone elses. I want good fuel economy and torque over WOT power, so maybe 13 afr is a better choice for me

 

Actually, I usually carefully word my posts to avoid injecting too much subjectivity. I only implied "unacceptable" - and only to the AFR above 7k with DJ132/4N - as those numbers are not subjective.

However, with a given mod combo, if a CVK setup loses trq/hp from 7k up, compared to a "better fueled" setup, I think it should be called "something bad"..

You have the mod combo for the best all around power curves/levels possible - to date.

If, however, you would prefer to maximize power curves below 7K, you'll need to reinstall your stock header and use DJ140/1N Lidless. Doing so turns your KLX's into a TRQ monster (MCM, Stock Header + FMF Slipon, Lidless, DJ140/1N)..

 

I still have a tough time with the TRQ monster and KLX250 in the same sentence... kind of an oxymoron... for any 250 for that matter. I guess that comes from riding a 650 for so long. They tend to put the TRQ in the monster.

But I get it... comparing stock to the modded one, it's relative.

 

K158 Main Jet installed. Needle set to 1N and washers stuck on top of the needle. Stock Spring, Stock slide hole. Kouba link 3 turns out. (and barely any popping on decel!)

My chances of getting a speeding ticket have increased exponentially. The bike gets up to speed much, much faster than with the DJ 132 or anything else included in the klx250s Dynojet kit. For those wanting maximun acceleration in the shortest time frame, this recipe is a winner. I'm still not sure if it's what I need, but nonetheless I had to try it out. It is fun, and it pulls hard right to redline as claimed.

Still doesn't have the oomph of a higher displacement motorcycle, but for 12 bucks it was a nice experiment with real results! I'll be testing the power offroad this weekend, time will tell if extra power above 5.5k rpm is really what I need.

I will be ordering a slightly smaller Keihin jet, and reinstalling the stock header pipe to see what the difference is in torque. The ability to pop the front end over obstacles is more valuable to me than doing zero to speeding ticket, or racing other small displacement motorcycles. Big bore is in the works, but I don't have the cash to splurge on that yet.

 

OK!.. And reinstalling the stock header + Lidless K152/1N will let you feel the heightened TRQ curve from off idle to 6.5K.

The charts indicate that both mod recipes produce approximately the same peak TRQ numbers with fantastic broad curves. it's mainly a shifting of the curve to favor the low end, with the Stock Header recipe..

 

Good to know KLXSTER! I was kicking myself for not ordering both main jets at the same time. Not a big deal. I'm sure someone in my town will want to buy the powerbomb header... should help pay for a seat concepts cover!

 

Ahh, you might wanna hold off on selling the PBomb.. The stock header recipe is really nice below 6.5k, but overall, it's curves are inferior to the curves of the Full FMF recipe you have now.. Your stock header recipe will finish (be done) making power at 9k-9.2k..