My experience has been that the four strokes do not work well with a pump unless you get one that is extremely large for the application. A 130 four stroke will barely work on the average 19 foot sled. Barely is not what you want in a sled, You want ample power to carry a load and to get on step quickly. Unfortunatley there is no 175 hp four stroke. If your gonna get the v6 your lookin at 200+ hp. I would not get a four cylinder, four stroke pump unless I was getting a small sled <17 feet. Regardless of 2 vs. 4 stroke, I would Stay away from the merc. Yeah I know the manufacturer really wants to sell you one but I would insist on the yamaha.