Hard cold start

[rupecopp]

I recently rebuilt my 02 ec200, and although it's running great I'm having real problems starting it when cold. I have to pull the choke out a kick it loads of times before it fires into life. Once hot out on the trails it starts no problem, and runs well. I also noticed yesterday if I come back to have a drink and rest it needs choke after its cooled a little when it didn't use to.

I have put a new plug in and checked all there, and also taken the carb of and given it a good clean.

Any ideas what to try next???