I have a 01 CR250 and was riding this winter in 30 degree weather and the bike and plug were great. The honda comes soo rich that their stock jetting worked good for my winter jetting. Stock settings are 420main,35 pilot,clip in middle,air screw 1 3/4out. Well after fighting with my bike for a while im all messed up. The other day I was running a 410 main and the stock 35 pilot clip in the middle. I was riding at sea level in tight single track and I was not hard on the engine and it was pretty much all below half throttle stuff. SO the bike was loading up on me so I figured it was time to go to summer jetting finally. The 410 was for spring type temps. I dont know much about jetting so i was playing it safe. So I put in the 400 yesterday and left everything else stock. Well it was way too lean in 60 degree weather. SO today I put the clip in the # 5 spot to richen it up. and it was way too rich. I dont know what to do. If im not going past mid throttle am I even using the main jet????????? My plug was white yesterday so thats why i went all the way to the bottom with the clip.