I looked but did not find a title specifically addressing this mod which has been great on my 2010. Below is a post I added to a thread in pre-2008 which discussed this under a different title, but I think it deserves its own since it is so productive.
Gen 2-ers, do the MC mod. With my Gen 2, black 2010, the MC "free performance" mod WORKED nicely. Did it a few days ago, after reading this and other threads. Mike's observations seem right on target.
Details, before the MC Mod:
Stock 2010 model with 10k miles, with these 2 mods done: desnorkeled, 2 holes in top of air box; 1.25" (the conservative) detweeted stock exhaust. Bike has always had a jerkiness at low (~2000) rpms, seemed unhappy under 2300.
After the breathing mods, I'd compared it to another totally stock 2011, and it ran away from the stocker in both 4th and 5th gear rollons, starting about 2500rpm. About 2 bikelengths in each gear...
Time for a good plug check to see if the stock mainjet, allegedly too rich in the stocker, was impacted by my breathing mods.
Elevation 900 ft, ambient about 85 degr F. Petrol: 87 octane Mobil regular (right, with 10% ethanol added to keep the Farm Lobby happy)
Did a good WOT plug check, courtesy of a nearly empty interstate hwy nearby (90+ mph sustained for a minute or so.). Plug was nearly white, but not blistered. Replaced plug with Iridium one from Eaglemike.com and then rode it to shop and then did the MC Mod.
Perhaps because excess anality, it took 2+ hours, along with valve clearance checking. 'Twas a struggle to get the valve cover out, had to tilt rad fwd for clearance. Not easy to advance cam by lifting the chain because of a boss in the head which appears to try to prevent chain from lifting off sprocket. So, after marking chain & cam sprkt, removed cam and did it. Also checked valve clearances which were barely in spec, at high end of the ranges.
After the mod:
Fired er up, n whatta difference !
Much smoother & more tractable at low & mid throttle. The admittedly subjective butt dyno says there's a bit more torque and also easier revving above 5000. Enuf more torque that I'll try a 17t cshaft sprkt in future (for a long, mostly flat TLH ride next month.) Haven't yet run another plug check, but it ... feels like it's running less lean, a good thing.
I'll run it again against that same stock 2011 when I get the chance, but even if it didn't further improve the power, it was worth it.