if 30 prop four choke pushed your boat well two stroke 48 jet outta push it about the same. If it's using the oil injection I'd get rid of that and just premix. You can't go wrong premixing yeah you use a little more oil but I'll take it over a vro system failing and burning up the engine. Just check the impeller sharpen and shim it as needed. Lots of debate on how to sharpen impellers but I prefer lilbluerude's method of sharpening the top side of the leading edges of the impeller only touching up the bottom to remove burrs. OBJ tells you to sharpen the bottom but the impeller gets less bite in the water if you do that.