I'm a rookie with bikes, but I just replaced the engine. The issue is that it is hard to start now. It does get going, but only if I turn the throttle like half open. Then it's initially rough, but quickly goes to idling fine. What should I ckeck first? How can you tell if the plugs are fouled?
I should mention that it has the 49 state engine with CA carbs, witch has a slightly different pilot setting than the 49 state carb.

Basically, what are the main factors in the starting process?

 

Petrol, Spark & Air, can't have one without the other. For fouled plugs, it's anything other than wot they should be, slightly tanned in colour. Black & sooty means a rich mixture, white 'N" powdery means too lean. oily means t-r-o-u-b-l-e.
Don't know much about your different state carb's (anti- pollution) requirements, (seen it in my manual & it scares the crap out of me).
but sounds to me like this could be the issue. sounds like your engine is flooding or running rich, either way maybe a carb adjustment and syc. is the go