We don’t mean to nag, but these are just some of the things you need to do to make a propeller testing session worthwhile.
“People don’t understand all the different variables and how stringent you need to be when testing,” said Dirk Bjornstad, brand manager at Mercury Propellers.
There’s more to selecting the right prop for your boat than simply going up or down in pitch. Adding or decreasing blades makes a difference. So does the amount of cup, rake angle, and blade area. If your boat has a stepped-bottom design, it’s going to have different prop requirements than a conventional one. Taking a closer look at all these factors will help you make a more informed decision.
“My first questions to a customer are, ‘What are your main goals? What are you looking to achieve?’” said Brett Anderson, president of BBlades Professional
Propellers. “The common response is, ‘I want to get on plane fast, I need great mid-range, and I want to go faster than my buddy.’”
But even the most experienced prop wizard can’t help you without having accurate knowledge about your boat, such as the engine manufacturer’s recommended maximum rpm (e.g., on a MerCruiser 8.2 MAG HO, the range is 4,600 to 5,000 rpm).
With fuel prices climbing in spring, Bjornstad said he was fielding calls from people looking to save gas money. The biggest misconception was that you could save money by putting on a prop with more pitch. Actually, it has the opposite effect. “This puts more load on the motor and you end up burning more fuel,” Bjornstad explained.
If you want to save money, shoot for the bottom end of your motor’s recommended rpm range. With the engine turning less rpm, it won’t burn as much gas when you make that top-speed blast.