Vision 180 Pro setup

[Warrenroadie]

I moved this from general discussion.

Good afternoon,

When I purchased this boat PTP was 4.50". My top speed was 63.5 at 5400 rpm's. Have been raising the motor 1/4" at a time. Top speed has decreased steadily with each motor raise, currently down to 58.0 at 5500 rpm's. I can trim motor to almost full trim below water pressure drops below 15 psig. My motor is a 150 Mercury Pro Max with 24P Laser II prop. As I give it throttle it is pushing front end of boat down appears that most of hull is in the water. If I back off of throttle front end appears to rise? I have a great hole shot. It can get on plane very quickly. I feel I need a different prop with a different pitch. I have a 6" Jackplate. Please give me some advise I want to maximize the performance on this little boat. Boat setup as far as fuel and tackle have basically the same during the noted conditions.

Thanks for your help in advance.

[XstreamVking]

Move the motor back down....63.5 ain't bad for a 150.....Try a diff prop like a chopper before you raise the motor. It is a better surfacing prop than a laser. Not a great fishing prop, but might be a lil faster.

[Warrenroadie]

Thanks! What pitch should I be looking at to increase my rpm's with a chopper design prop? I've been told I need to be around 6500 rpm's WOT with this motor.

[XstreamVking]

Same pitch would increase the r's somewhat from the increased motor height you could run. You are at 4% slip now, which is real good. If you change to a chopper and slip increased to 7% and you could turn 6000 r's you would be at 69 mph. Here is the slip calc program http://www.mercuryracing.com/prop-slip-calculator/ It gives you an idea of the diff aspects of speed vs rpm vs mph. Your gear ratio is 1.87 I believe....You will learn more by trying diff props and plugging them into this calculator...It is not fool proof, because props are variable, but it is a tool.

[Warrenroadie]

Thanks for information and caluculator. So a chopper prop characteristic is to slip more than my Laser II, so in turn I will be able to turn my rpm's. I was told this motor needs to be turning 6500-6700 WOT rpms. I wish there was a way to rent/lease props and then purchase the correct and/or best prop for your boat/motor setup. Have a great day.

[XstreamVking]

Lot of diff props, chopper may not be best. They do give a ton of bow lift. If your trimming a lot it may help. Slip is good sometimes and not good sometimes. Depends on the prop and boat combo. The prop you have may not be as bad as you think for overall efficiency...