Just a quick observation and question (bike is a USA 2018 FI model - no performance mods - Dunlop D605 tires still on).
I installed a 45t rear sprocket and 108-link chain this past weekend (still using the 14t front). I weigh approx 180 with gear, and running wide-open throttle on a level highway, I am seeing about 8,500 rpm's with a gps-verified top speed of 72.3 mph. From what information I can find, does this sound about spot-on performance-wise for this bike?

 

Yes, horsepower maxes out at around 8600 rpm My gearing chart for the 2009 up shows 75.52 at 8600 rpm with an actual tire diameter of 25.3 If you would like a copy of the spreadsheet I have attached the .xls file.

 

Thanks! I took a quick look at your spreadsheet, looks like I'm really close. Looking forward to some off-road riding with this new combo (14/45), I was pleasantly surprised with just trying the 13/42 combo. I found the 14/42 OEM combo had me prone to stalling a lot when crawling up hill.

 

14/45 is nearly the same as the 13/42, thing is it will cause less wear, because the loads are spread over more teeth. Nice part too is the ability to go higher with a 15 or lower with a 13 if needed. I used that sheet to compare tire sizes when looking to have a set of roll in SM wheels for my KLX650, The variables are the tire size the sprocket sizes, and the rpm. You can see what speeds are at a set rpm in any gear with whatever tires. I pulled the tooth count from Kawasaki's parts schematics, then set up the calculating cells to do the numbers. download or copy the file if you have a new enough version of Excel.