Thanks for all the advice on this, too bad all of us are spread all over the world! would like to meet up for a ride some time!! I did the mcm mainly to quiet the intake growl. I did the carb jetting / lidless set up following KlXsters recommendations. (anyone that has not done that i highly recommend!!) - thank you to KLXster for getting me hooked on the "modification crusade". After all the reading about cam timing, it dawned on the that the truck i drive everyday has the same priciple. Variable Valve Timing - solenoids on the camshaft ends that adjust the cam positions / valve timing base on throttle input / load / vacuum & RPM's . Interesting.........

 

Again, just let the experts define the results then consider what is done in the MCM...

Camshaft Shootout: Lobe-Separation Angle Tested and Explained. Read what the experts find and say.

My one comment dealt with rideablity at extremely low rpm - nothing noticeable - and the fact that it just didn't matter to anyone who rides the bike in a normal fashion. The problem with cars relates to vacuum, which really isn't a problem with the KLX, nothing much operates off of vacuum that would present problems.

My other comment is whether the cam timing has a positive or negative effect on the big bores. Just not seeing how it would not probably have better performance that may not be noticeable via the butt dyno. Seems easier to handle or smoother power may not actually provide a boot in the butt.

Lastly, is it pure luck that the cams perform better with the narrower LSA, or was it that they took the cams they had and altered the LSA to reduce overlap to get a cleaner burn for EPA/DOT purposes? It may just be fortunate circumstances, but again, the intake cam shaft is the same one used since 1994 in every 250/300 and the exhaust may very likely be the exact same, with the difference being in the placement or other differences in the KACR since it seems there were different ones even among the newer bikes between 2009-2019. But then there are the cam sprockets...

Just sayin' clearly one of the cams and likely both are likely the same through all the years.. Not sure about the cam timing on all of them though. Seems the pre-2005 KLX300 has different sprockets than the KLX250/300 from 2005 up based on part number. The KLX250/300 from 1994 to 2004 runs different cam sprockets. Might be worth looking at to see what Kawasaki did with the older 300 different from the newer 250 since both are 32T. What was this cam set supposed to run at? You might find the 300 has different timing made for those cams that have been used in all the bikes. Pandora's box opens again. I may see what it costs to get a set of the sprockets on ebay just because.

Those are my small contributions. The rest is from recognized credible expert sources.

 

Came back from a test ride about an hour ago. Before any of the mods (klxsters carb mods) or the mcm, The difference between stock to now is when it was stock, it felt like I was riding with a parachute deployed. It feels totally opened up right now, and you can tell how good the motor can breathe!! How much horsepower does a stock 250 put out compared to now with the modifications?

 

Sweet. Good job! 19HP is stock I believe. Not sure what your gaining but I'm sure someone more knowledgable will chime in. Just wondering, how does it feel with the just the first Klxster mod vs. after the MCM? What year is your bike? I'm 6'0" and that seat killed my *** and knees. You ,being 6'2" , have you redone your seat yet? I paid $250 to widen and raise it 2" and it made a world of a difference. First mod I did and worth every penny.

And yes, the bike stock sounds like a sewing machine and feels like a moped.

 

@mac71 , the power with your build (MCM+stock header&performance slipon+lidless CVK) is roughly 22 hp/16.5 lb ft trq. This is about a 10% increase in HP, BUT, roughly a 30% increase in TRQ !

Peak numbers do not mean anything - just bar room bragging rights - the "real deal" , that you are now feeling, is the fact that your power increase is occurring over the entire RPM range, not just in a "bump up" at some point in the RPM range. This is the kind of performance increase that makes a bike feel radically different. Your bike can run circles around a stock KLX now. My wheelie vid below was when my bike was set up exactly as yours is now (BTW, I have stock sprockets)...

You now have the most power possible with the stock header in place. Enjoy !

P.S. There is one more "next level" of performance available to you. It is to add a performance header and change to a DJ144 main jet. The change for you would be that your "biggy power" pulls hard all the way to redline (10,500 RPM) instead of tapering off past 8500 rpm..

 

Seat concepts seat is on the way!!! Ordered it like almost a month ago! But the pandemic held it up. Can only rode the bike for like 45 minutes, then the pain in the tailbone starts!! As for the power, Klxster explained it perfectly in his post right above. That because he has tested it on a dyno, so it is a hard fact!! Just do it, and ride the bike, it just wants to go! You can really feel how it pulls hard and even the whole way through The RPM range. I was on a brand new paved road also that was like glass so it was a great run.. Intake growl is at least 50% reduced, and the exhaust is more “brappy”- not even sure if that’s a real word but it explains it perfectly.
I’m running with an fmf q4 stock header.

 

Oh, it’s a 2014. Found it about 6 months ago with only 800 miles on it!!

 

FYI, if Mac71 and Ekim250 were to race, here's what the data would suggest.

Starting from a steady speed, 2nd or 3rd gear, and at 3000 rpm - both bikes snapped to WOT and held WOT to redline (10,500 rpm)..
Mac would take lead and steadily pull away from Ekim. To Ekim, the race would look lost.. BUT, once Ekim's bike gets past 7000 rpm, he begins to keep pace with Mac and then begins to catch up to Mac. While I cannot predict the outcome with certainty, Ekim's bike will increasingly outpower Mac's as RPM's rise past 8000 rpm. For instance, by 10,000 rpm, Ekim is making roughly 3 hp more than Mac..

It would be fun to watch..

 

This is why we all did the MCM.

 

That works for me!! I'm not a speed demon - but getting there is the fun part!!!