I have a 2005 Stratos 285 XL with a same year 150hp Yamaha VMAX Carb motor. I have no jackplate. The boat came with Michigan Wheel Balistics #345937 14.5" x 24XL prop on it (this prop had no ports in it). I purchased the boat new and have not had any issues other than a spun hub years ago. It came out of the hole quickly and could easily achieve 60 mph in the winter and around 58 in the summer with a typical load. Fast forward to about a week ago I threw an ear on the prop. Ordered the same prop (or what is now the current version that has 3 @ 3/8"+/- ports) but what they sent ended up being a #953524 14.75" x 24. I didn't think the extra 1/4" would make a difference so I put it on the boat and took it to the lake. Got up on plane just like the old one but when I trim up at about 1/2 trimmed the prop blows out or starts to slip (not sure those are the right terms but the boat actually slows down and RPMs increase) It also does the same thing if I make a hard turn. The best I can get out of it is about 52mph and 5300RPMs. I trimmed it way up one time just to see if it would go away and it felt like it was chime walking which the boat has never done. I also noted that I am getting consistent 30 PSI water pressure. I took it back to the garage and measured the prop to pad distance and it is at 4-1/4". From all my reading I have done in the forum I realize that the motor is probably to low. I have one more set of holes on the motor mount I could raise the motor to and achieve 3-1/4" prop to pad. I am a novice when it comes to boat set up and am looking for advice on what to do. Are there other factors i am overlooking like different cup on the prop? Can 1/4" increase in diameter really create such an issue? My first thought was just send the prop back and see if they have the 14.5" they can send me but after I realized my motor appears low am not sure if I should try to raise my motor first (I also am not really sure of the best way to do that at my garage). Any advise would be much appreciated.