I seriously doubt that 5 to 10 degrees is gonna cause any probs. There's enuff shaking and agle variations going on during starting and riding to ensure that enuff gas is getting into the bowl. Most engines can run up to about 30 to 45 degrees of tilt before cutting out.
One simple test you can do is to slightly loosen the float bowl on the carb to determine if the float valve is operating correctly. If it leaks and continues to leak, the valve aint shuttin off which is causing the engine to flood.
You may have to take the bowl all the way off to see if the carb is gettin enuff fuel. Simple test for that too. Take off the bowl, hold it underneath the carb and let it fill up (that is, if the gas IS getting to the carb) then slowly lift the bowl up to the carb, as if you were gonna re-attach it, to see if the float will shut off. If it shuts off, then all's well. If you don't have gas running into the carb at all, then that's another story.....good luck.