I don't see what the problem is. Maybe the paint is slightly thick around the nipple. You can take some sand paper or a file and shape that nipple a bit so the breather hose slips over a little easier. You do want a slightly tight fit. If you do file or sand plug the breather hole with something to keep any shavings or dust out of the breather nipple. What year is your bike? Is it an '03/'04? Where is it from? That doesn't look like a VIN # on the engine.
Mine is an '03, Indian market model. The nipple doesn't have excess paint, but it does have a weird set of barbs on it, which may be adding to the problem. I'll try a new clamp and if that doesn't work, try one of the hose connectors others have mentioned.