What that graph fails to show is the most important area to have torque, which is low rpm. I have ridden my riding buddy's XR650L a lot and it will blow my KLR in to the weeds at lower speeds. Hell, my little XR400 will, too. All of Honda's XR engine are extremely torquey engines, but they run out of steam very quickly. You can make them rev to high rpms, but the bike doesn't really build any speed for it. They love to be short-shifted. Stab a XR650L while rolling along in 1st or 2nd gear and they will stand up on power alone. The KLR needs the clutch dropped to do the same.
That said, the KLR will still beat an XR650L in a flat out dag race ( in my experiences with my buddy), but I credit that to the KLR's ability to rev well... never thought I'd type those words...lol. I know most guys post about keeping revs down while cruising, but I was pleasantly surprised the first time I ripped through the gears on my KLR , going to redline in every gear. It really pulls great! Glorious sounds, too. I fully believe that graph. A KLR will eat a XRL on topend, hands down.
This reminds me of something I've thought about asking several times, but figured I'd get laughed at. lol
Back in my drag racing days we used to play with valve lash to get an engine to produce power where/ how we needed it. Loosening the lash on the exhaust valves ( effectively reducing the duration) will always make more torque across the rpm band. Sometimes the dyno would show huge imrovements. Like, 30, 40 or even 50 ft/lb worth. It depended on the cam profile and other variables, but it was a consistent way to ekk out some launching power without sacrificing too much top end, run-for-the-stripe hp. Has anyone every tried playing with valve lash on the KLR to see if they could find some more bottom end grunt?
Are you not yet familiar with, 4 one inch holes in the top of the dirty air box, 2 turns open on the low speed mixture screw, a .020" shim (or 2) under the mid-range needle and drill a 7/64th" vacuum air hole in the bottom of the KLR throttle slide? This improves the low to mid-range power and response.
Then are you not yet familiar with the "MC Mod", "Free Performance Mod", "Exhaust Cam Advancement Mod"?
This mod also enhances the power and response between 1500-6500 rpm on the GEN2 primarily! Sometimes helps and sometimes hinders a GEN1, we don't understand WHY.
This mod advances the exhaust cam ONE full tooth. Simple, Cheap & Easy! And easily reversible if your engine doesn't like it.
I've been looking forward to riding with my long time friend Keith Collins, who purchased a 2016 XR650L, last spring. He purchased a 2009 KLR650 (his 3rd KLR) from us after riding his KTM620 RXC with me and friends. (I like to compare "performance", side by side.) He used to race AMA District 37 Hare & Hound.