4-blade vs 3-blade

[beckoning]

Help me understand the difference in low speed performance, maneuverability, and torque between 4-blade and 3-blade props. I have a 9.9hp 4-stroke kicker with a 3-blade and am considering switching to a 4-blade for low speed maneuverability and torque. Before spending $$ for a 4-blade, I would appreciate some general opinions of what to expect by switching to a 4-blade. I need more maneuverability, not speed. Any advice would be appreciated.

 

[Slow Ride]

Re: 4-blade vs 3-blade

Generally speaking, a 4 blade prop will give you a better hole shot but will cost you a little on the top end. That said, on a 9.9hp motor I doubt you will notice any real difference. Usually very heavy boats or guys like me who want to be able to fish shallow water and need to "jump up" on plane very quickly in shallow water will use a 4 or even 5 bladed prop in some cases. But like I said, the difference for a very small motor would make it not worth the money for a good 4 bladed prop in my opinion. As far as maneuverability, I'm not aware of any noticeable difference. A few years ago I had a 24ft bay boat with a Yamaha 250hpdi and I kept bot a 3 blade and 4 blade prop at all times. I used the 4 blade in the shallow bays and tidal flats but would use the 3 blade if I went offshore or on long runs because 3 blades are generally more fuel efficient and faster.

 

[tpenfield]

Re: 4-blade vs 3-blade

+1. . . . On a small engine it is not really worth it.

 

[beckoning]

Re: 4-blade vs 3-blade

Generally speaking, a 4 blade prop will give you a better hole shot but will cost you a little on the top end. That said, on a 9.9hp motor I doubt you will notice any real difference. Usually very heavy boats or guys like me who want to be able to fish shallow water and need to "jump up" on plane very quickly in shallow water will use a 4 or even 5 bladed prop in some cases. But like I said, the difference for a very small motor would make it not worth the money for a good 4 bladed prop in my opinion. As far as maneuverability, I'm not aware of any noticeable difference. A few years ago I had a 24ft bay boat with a Yamaha 250hpdi and I kept bot a 3 blade and 4 blade prop at all times. I used the 4 blade in the shallow bays and tidal flats but would use the 3 blade if I went offshore or on long runs because 3 blades are generally more fuel efficient and faster.

thanks for taking time to answer. This helps. You may have saved me some $$.

 

[Rancherlee]

Re: 4-blade vs 3-blade

What's the main function of the 9.9? main motor on a John or a Kicker on a big boat? A 3 or 4 blade "high thrust" labeled prop can make a noticeable difference on a Kicker where you need thrust for control. I went from a 2 stroke 9.9 evinrude with a normal 9.5-10" prop to a 9.9 4 stroke high thrust Yami with a 12" prop and the difference is night and day for control due to 2x the blade area. It's all about what your intended use is!

 

[beckoning]

Re: 4-blade vs 3-blade

Rancherlee, thanks for the info. The 9.9 Mercury 4-stroke is a kicker on a 2000lb, very deep V aluminum Sea Nymph Great Lakes Special that fishes Lake Michigan. It is connected to the 100hp via a steering rod. I am considering a 4-blade to facilitate low speed (2-3mph) turns into 2-3' waves and 9mph+ wind. When turning into that combination, if the wind and waves are coming from the same side of the boat the kicker is on (port side), the motor's angle disadvantage and very deep V work against turning, so my only option is to rev the kicker for a slow turn which kills trolling during the turn. I adjusted the steering bar to maximize the turning angle and that helps. All worked well with my 4hp 2-stroke Evinrude, but it could not handle waves or wind very well, so I upgraded. My next step is to consider a 4-blade to improve low speed trolling and turning. Your insights will be appreciated.