Posts: 4,335
Threads: 0
Joined: Mar 2008
Reputation:
0
quick question. i would assume based on nothing more then the physics that a 4 bladed prop displaces more water then a 2 bladed prop (for a 8 horse kicker that is) but other then that whats the differance? i would also venture a guess and say weight. reason im asking is i was looking over bass pro dot com and noticed they had a sale for evenrude 8 horse motors, 2 bladed props. i bought TS's boat from him, and dont have ready access to call him and ask if he has a spare. has anyone ever noticed a differance when going from these two? i have also noticed from time to time a 2 bladed vs 4 bladed propr on peoples bow mount trolling motor, but i have never seen one on a stern mount motor, why is that? is it simply because a stern mount motor is designed to push the entire weight of a boat and needs the extra blades and a bow drive is to slowly pull the weight of the boat? just curious is all, i saw these things and steam started comming out of my ears from thinking to hard.
[signature]
Posts: 65
Threads: 0
Joined: Mar 2008
Reputation:
0
You have the basic idea.
A 2-blade prop will have less "grab" in the water but give you more top-end speed due to lower drag. A 2-blade prop would be what you'd want to use for maximum on-plane speed on a flat-bottomed 12' aluminum boat.
4-blade props harness more of the torque out of the motor and are better for accerating a large load quickly. A 3-blade or 4-blade would be much better if you were using the outboard on a 24' deep-v fiberglass boat as a trolling kicker.
4-blade props are comonly used on underpowered i/o boats to help improve the hole-shot when water skiing but sacrifice about 5-10% of top-end speed
I think the main reason bow-mount motors use 2 blade props is that they are only used for slow and easy manuevering while standing on a casting deck and you don't want to end up in the drink.
[signature]
Posts: 33,349
Threads: 418
Joined: Feb 2002
Reputation:
33
Welcome to the site Bvs and thanks for helping kochanut out with his question. It's good to know someone on the site has experience with the different props types. WH2
[signature]