2011 crf450 very hard to start

Hey guys, first post for me. I just bought a 2011 Honda crf450r yesterday, which had a top end rebuild done by the last owner just 3 months ago (10.5 hours riding). The bike is ultra hard to start when it’s cold, you can kick it all day long and it just sounds dead, no hint of wanting to start. If you can get a good enough run off down a hill, it’ll bump start, it runs fine when it’s on. Once it’s warm it’ll kick over after a few kicks but still not as easy as it should be. I’ve had every model of crf450, and never had an experience like this. It feels as if it’s got a lot more compression than any other crf I’ve had aswell. the kill switch on the bike is toast, like it’s stuck in, but I’ve unplugged that to see if it’ll start without it, but still no difference. I’m at a loss at to what it could be. 

Any help would be greatly appreciated. Thanks guys