What prop to get

[iggyw1]

I have a Nissan outboard on my boat. It is still in storage here in Mich., so I do not have the model number on me, but I really don't know if my question would need the model number or not. It is a 1992 model, 70 H.P. motor. I am thinking about getting a new prop for it, and I was wondering about the difference between a three blade and a four blade prop??? What would happen to the RPM's and what would happen to the speed off the line and top end if I go with the four blade prop?

Thanks for your input on this.

 

[Scott Danforth]

kind of need to know your current WOT RPM, GPS speed, what you are starting with, etc. there is a list of questions in the stickies that need answers for any prop suggestion.

 

[iggyw1]

OK Thanks. I will need to wait on that until I get her out of storage. I probably would not be getting a new prop until then anyway. Thank you.

NOTE: Don't know what pitch I have on there now, but it is a three blade prop. I know right now I am pushing 5300 RPM at WOT. Doing 28 MPR in a 16.5' Smoker craft. Does not take too long to plane. I use the boat strictly for getting in and out off the lake, no skiing or trolling with the motor. I use my kicker for trolling. I guess I am trying to get more speed (bottom line) if I can without going to a bigger motor. I believe my boat is rated for a 90 H.P. motor and I have a 70 on it.

 

[ahicks]

Pretty safe bet 4 blade is more likely to cost you speed than to make it.

 

[iggyw1]

Pretty safe bet 4 blade is more likely to cost you speed than to make it.

Yea, that's what I am finding out when I Googled the four blade props on the internet. All the sites I checked out state that I will get better speed out of the hole but lose top end speed. I will stay with my three blade prop I think, because I am after more speed, not less. Thanks!

 

[Sea Rider]

Those OB's wot revs 5-6K rpm, will need to drop 2 prop pitches to pull wot revs near max wot rpm range, hole shot will be much bettered as as when achieved just 5300 wot revs as were loaded.

Why is it that near everyone wants to go after 4 blade props when there's a world of OEM 3 blade alum props that works fantastically well, it's just a matter to prop OB right for combo to fly, not out of this world though.Will need a tach if excellent working order for that task.

Happy Boating

 

[iggyw1]

Those OB's wot revs 5-6K rpm, will need to drop 2 prop pitches to pull wot revs near max wot rpm range, hole shot will be much bettered as as when achieved just 5300 wot revs as were loaded.

Why is it that near everyone wants to go after 4 blade props when there's a world of OEM 3 blade alum props that works fantastically well, it's just a matter to prop OB right for combo to fly, not out of this world though.Will need a tach if excellent working order for that task.

Happy Boating

LOL I even saw some five blade props advertised on line and watched the videos. I didn't know that a 5 blade prop even existed.

 

[Sea Rider]

Stay with 3 blade alum OEM props and prop engine right...

Happy Boating