A little background - 100 hours on the bike, checked valves again and they were tight. Intake were .8, .9 ,.10 (spec is .10-.15) Shimmed them all to .13. Exhaust were both .15 (spec is .18 -.22) Shimmed them to .20. Put in new OEM piston and rings, new OEM timing chain. Go to start it after top end, kicking with choke on, a couple short fires but wont start (has always started well with choke on when cold) After a lot of kicking tried a couple with hot start on and it starts? Went for a ride, seems to run fine. Again yesterday went to start it, will only go with hot start on. Once warmed up it starts normal, no hot start, no choke. I have the carb off now and am going to blow it all out. Does it sound like something related to the valve clearance or when I had the carb off did I get dirt in it? Thanks in advance for opinions.