Hello,
I am at a loss with props. I have a Susuki 70 hp engine and I get 18 mph top speed with just me in the boat. I figure that I should be getting around 25. I am sure it is the prop. I know nothing about props. What do you all recommend for a good prop for this engine? Thanks for your help!
Marc
Susuki 70 HP Prop
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Frank C
Welcome aboard.
First things first, adjust your expectations. My Suzuki 60 is good for about 21 on my 26X. You didn't say which boat you have, but if it's a 26X I'd guess your 70 might go 23 mph, best case ... less if you have a 26M. Still, you're correct that 18 mph is a bit slow, but you didn't say what your max RPMs are. The correct prop will permit your outboard to reach the upper end of recommended range. With a lightly loaded boat you should probably reach 5,800 rpms.
Most here are using a 14x11 prop (that's 14" diameter x 11" pitch). You would really need more than 70 hp to use a higher pitch, like 14x13. The new high-tech 90s might work with 13-pitch, not your 70.
The problem is that our Mac 26, both M and X, are too much weight and wetted surface for these motors. You'll find the best performance from a dog-eared prop with lots of surface area, frequently described as for pontoon boats. The best reports I've seen are for the Quicksilver prop, 14x11 ... unfortunately it's not available for a Suzuki hub.
Regardless of how much feedback you receive in this thread, it won't be as thorough as doing some background reading. This has been discussed many times ... the archives should reveal about a half-dozen prior threads on props for mid-range outboards. The search button appears at top-center of every page.
I'd try a search on Suzuki prop, and click the 'all terms' button.
If you're uncertain about props in general, search on diameter pitch, and click the 'all terms' button.
First things first, adjust your expectations. My Suzuki 60 is good for about 21 on my 26X. You didn't say which boat you have, but if it's a 26X I'd guess your 70 might go 23 mph, best case ... less if you have a 26M. Still, you're correct that 18 mph is a bit slow, but you didn't say what your max RPMs are. The correct prop will permit your outboard to reach the upper end of recommended range. With a lightly loaded boat you should probably reach 5,800 rpms.
Most here are using a 14x11 prop (that's 14" diameter x 11" pitch). You would really need more than 70 hp to use a higher pitch, like 14x13. The new high-tech 90s might work with 13-pitch, not your 70.
The problem is that our Mac 26, both M and X, are too much weight and wetted surface for these motors. You'll find the best performance from a dog-eared prop with lots of surface area, frequently described as for pontoon boats. The best reports I've seen are for the Quicksilver prop, 14x11 ... unfortunately it's not available for a Suzuki hub.
Regardless of how much feedback you receive in this thread, it won't be as thorough as doing some background reading. This has been discussed many times ... the archives should reveal about a half-dozen prior threads on props for mid-range outboards. The search button appears at top-center of every page.
I'd try a search on Suzuki prop, and click the 'all terms' button.
If you're uncertain about props in general, search on diameter pitch, and click the 'all terms' button.
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Matt19020
- Captain
- Posts: 576
- Joined: Sat Jul 15, 2006 1:29 pm
- Sailboat: MacGregor 26M
- Location: Middle River, Chesapeake Bay MD...2007 MacM Suzuki DF70 4-Stroke ..... "My Time"
- Contact:
I have the Suzuki 70 with 14X11 my best speed ever was 21 with no bottom paint and empty ballast.
With the bottom painted and fully loaded and with water ballast, I see about 16 -18 regularly. I rarely drain the ballast out and if you run full throttle you suck the fuel right down. I would rather run at about 7-8 mph.
I just get no enjoyment out of the noise of a winding motor. Thats just me ... I know I can get more out of it if I try another prop or make the boat lighter but right now I enjoy the "cruising" aspect to much to worry about the speed.
With the bottom painted and fully loaded and with water ballast, I see about 16 -18 regularly. I rarely drain the ballast out and if you run full throttle you suck the fuel right down. I would rather run at about 7-8 mph.
I just get no enjoyment out of the noise of a winding motor. Thats just me ... I know I can get more out of it if I try another prop or make the boat lighter but right now I enjoy the "cruising" aspect to much to worry about the speed.