Had some time so I buttoned the 290 kit up tonight and took it for a rip. My spark plug boot was broken and I was going to wait,but then I decided to rob the one off my rmz450-it worked. Took a few kicks to get started. St the compression stroke it sometimes.is stiff. I expected this with a big bore kit. Once warm it starts in 1 kick but if you catch the compression at the wrong spot-its tough. When I first got on it-i could immediately feel more bottom end. The stage 2 hot cams make a little more noise than stock. Not a bad noise,just more valve train noise. Throttle response was just as good as stock. It spool up just a hair slower if pulling a taller gear. The bike has to be ridden exactly as it is-a big bore 250f lol. It still revs and feels like a 250f,just a lot more power and everything is happening at a lower rpm than stock. It has good bottom end,but what actually impressed me the most was the mid range. If you like strong mid range power from 6-10k rpm,this is it. Past 10k to the rev limiter,it pulls clean. Didn't really sign off or do anything weird just kinda hung with the same power from say 10k on. I was running a very rich map and had a quiet insert in the FMF 4.1. It will really be interesting to see how it feels when its properly mapped and has a free flow exhaust. So far I am really happy. It now has balls down low and an awesome mid range punch. My gripe would be the starting-my bike started effortlessly before the big bore and cams. Now I have to get the piston at the right stroke for it to be a 1 kicker-as it breaks in this may get better. Second gripe- if you lock up the rear wheel and dont watch the clutch-it will stall. No bump starting this thing-it will slide. Lastly, I felt the rear 250f wheel might be a little too small. I could feel the rear slipping more than before. I will try the Rmz450 wheel out. Gearing felt OK for now. A little too tight on faster parts of track. The trans didn't seem to like 2nd to 3rd gear shifts under load,which was not an issue before. As things break in and I spend some time,my opinion may change or I will find adjustments. After being off the Rmz for a couple weeks-my fork felt like a sledge hammer. Going to dig into the midvalve and soften it up a bit. Rear shock felt OK,but the rear tire wanted to slip too much out of turns to tell.