finally got some decent water to open up the new South Bay 520CR with a Evinrude 90 pontoon series. Got up to about 19 mph at 5700 rpm. It was windy and we were in a weedy area. Is that reasonable? I need to buy a spare prop and am wondering if I should stay with the same prop or change it up a bit. Boat and motor plus fuel and two adults weight about 2700 lbs.
Try it again on a nice day and average the readings for 2 back to back runs 180° apart to negate the effects of current and/or wind.
Your 3-cylinder 90 HP Pontoon series outboard has a recommended rpm range of 5000 to 5500. It is best to prop as close as you can to the redline rpm with a light load onboard so as to not lug the motor when you take on a large number of people and gear.