Sod Farmer
Cadet
- Joined
- Jan 15, 2008
- Messages
- 18
I've learned alot from this board already, but I need a little help. Most of the threads I've read focus on the pitch of the prop to get the desired rpm's for any boat/motor combination. With that being said, I also understand that props with less pitch and more surface area are better at moving heavier loads. Some of the smaller outboards such as the Mercury "Bigfoot" or Yamaha "High Thrust" engines (60 hp max with either manufacturer) have these larger props with less pitch specifically designed for pontoon applications. Mercury, for example puts a 14x11 prop with little or no rake on their 60 hp "Bigfoot" I am unaware of any props for a larger engine that are similar in design to the ones found on the Mercury "Big Foot" or Yamaha "High Thrust" engines. I am buying a new pontoon that I will equip with either a new Yamaha or Mercury 90hp 4s engine. I plan to see what type of performance I get with whatever prop the dealer puts on it and go from there. When I look at all of the different props available for these engines, I know that I will need to get one with the correct pitch to give me the correct rpm's. However, there are varying degrees of rake and cupping that also affect performance. Given the fact that this is a pontoon that won't be traveling at speeds usually produced by a 90 hp engine, what design features should I be looking for in a prop? WOT should produce a top speed somewhere in the mid 20's. With my application, is it as simple as just getting a prop that gives me the appropriate rpm's at WOT? Are there any companies out there that make props similar to the Mercury "Bigfoot" props that would be useable on a 90 hp outboard?
