A time ago ,I did some extra motor work on my 650 R ('00):- HRC piston - Knibblewhite valves (intake 1mm OS, exhaust standard) - Hotcams stage 2 - cleaned /matched up the head,nothing radical. The carb is a a Mikuni Tm40,no probs before,great power.Other mods before: air box mods(12 holes of 35mm), no back fire screen,No Toil filter,Mikuni TM40, Evo (Monnier) exhaust line,stock motor.Bike is in SM trim : 15x 42 gearing. With the extra mods,the bike was run in with richer carb settings ; from 25 to 27.5 pilot,main from 157 to 165, the leaner needle (Bruce Specs) but 1 clip richer. The bike wouldn't run fine(bogs,sputters) with the richer settings. I dropped the needle and the main to a 157. The bike runs fine now but wound idle longer than 10/15 sec,sometimes dies on traffic lights etc. Sounds lean, I tried some airjet and pilot settings but nothing really helps.The bike starts/runs fine warm or cold.No bogs,sputtering . I have a spare crank with a Falicon rod now so I can put a 680cc kit on it.I want to solve the idling problem first. I put the OEM Honda cam back in again yesterday and the idling problem is gone, cold - still Little rough when hot but no stalling. Could the Hotcams be the problem or the head work? I just cleaned the ports a little,matched the intake piece .. let the intake rough enough( I think).I smoothed/matched the area where the valve seats meet the head, both on intake and exhaust. The valves were done by a pro (4 angle job). Anybody probs before with the stage 2 or with head work?