I have a 1991 70 H.P. Nissan motor. I removed my prop in hopes of getting it repaired during the winter months, it has some slight damage to the blades. The only markings at all that I see on my prop is the number 12 that is embedded right into the side of the prop. Would this be the pitch of the prop or the diameter of it? There are no other numbers or letters anywhere on the prop, inside or outside. If this 12 indicates the diameter, how can I figure out the pitch? I assume a prop shop can figure that out when I take it in for repairs,, correct? I am thinking they can tell me both, the diameter & pitch of the prop that I have, but I am not sure, Thanks!
Announcement
Collapse
No announcement yet.
What's my pitch?
Collapse
X
-
Originally posted by pvanv View PostSo you have either an NS70A2 or an NS70B. Year is irrelevant on these.
Yes, the 12 is the pitch.
Comment
-
Changing diameter on an OB prop has minimal effect. You have a nominal 12 pitch now.
You can see the OEM props available at https://tohatsu.com/accessories/prop.html
Typically any prop shop can repair damaged blades. If you need a re-hub, consider a new prop, and keep the old one as a spare.Paul
Certified Tohatsu TLDI Technician
Buffalo NY USA
Comment
-
Thank you very much for your help. I appreciate it. Fortunately, the hub looks great. The blades are not really too bad at all, but they can use a repair to make them like new. I will also get a new one if I can find out the pitch that I have. I do not want to change the pitch as I am very happy with the performance of the prop that I have.
Comment
-
Diameter is all about what the prop manufacturer wants to play width, pitch is all. If that's the original prop the motor came with, how do you know that performs top. You should change the factory delivered prop which is usually a medium pitch to at least one lower one to increase a bit the wot rpm range towards middle to max of its wot rpm range which is 5500 to 5800 rpm. For that will need a tach, does the motor has one ? Running any motor with an optimized prop as usually loaded it's a day/night boating difference..
In reality the motor needs to work inside it's factory wot rpm range, running happy is no indication whatsoever at which wot rpm the motor is working as usually loaded.
Happy Boating
Sea Rider 320, 380 Sibs, 450 Rib, 2 Strokes Tohatsu 5,18 & 30 HP Proud Smokers
Comment
-
I am running at 5600 RPMs at WOT, and I am doing 34 MPH with me & my cousin in the boat (we both weigh 380 pounds each), so I am happy. I have a 16' 7" alluminum Smoker Craft. I do not know if the prop I have is original or not, but I do not want to go over 5600 RPMs so that's why I am happy with my prop. The book that I have states the RPMs should be 5500 to 5600. IEven if I can go to 5800 RPMs and I only gain (1) MPH, is it worth running the motor at 5800, the very max.? Isn't that pretty hard on the motor for one MPH, or am I thinking wrong on this point? Thanks.
Comment
-
Originally posted by pvanv View PostYour WOT is OK. anything around 5500 is the sweet spot.
Comment
-
Right on, 5600 wot revs corresponds to the older models, 5800 wot revs corresponds to the newer 70 D model. You're there nothing to improve already running at max wot as loaded which is excellent at whicherver throttle setting you like. If plan going for a new prop install same as previous..just check diam and pitch.
Happy Boating
Sea Rider 320, 380 Sibs, 450 Rib, 2 Strokes Tohatsu 5,18 & 30 HP Proud Smokers
Comment
-
iboats Boating Forum Directory
Over 100,000 Questions & Answers
-
-
Outboard Motor Topics
Mercury Outboards
Johnson Outboards
Evinrude Outboards
Force Outboards
Yamaha Outboards
Mariner Outboards
Suzuki Outboards
Honda Outboards
Chrysler Outboards
Tohatsu Outboards
Nissan Outboards
Outboard Motors: non-repair
Vintage Outboards
I/O and Inboard Topics MerCruiser
OMC I/O, Inboard
Volvo Penta
Propeller Help
Boat Propellers
-
Boat Repair and Products
Boat Building and Repair
Fiberglass Boat Repair
Marine Electronics
Boat Trailers and Towing
Boat Names
Boat Covers
Boat Parts
Boating Activities Talk
Boating Topics and Questions
Boating Activities and Destinations
Boating Blunders
Boat Shows
Wakeboarding
Water Skiing
Fishing Discussions
Freshwater Fishing
Saltwater Fishing
-
Boat Type Topics
Aluminum Boats
Bass Boats
Bowrider Boats
Center Console Boats
Cruiser Boats
Cuddy Cabin Boats
Deckboats
Fishing Boats
Fish and Ski Boats
Houseboats
Jet Boats
Jon Boats
Pontoon Boats
Powerboats
PWC Forum
Ski Boats
New Boats
Used Boats
Boat Manufacturers
Boats (250+ Manufacturers)
Bayliner Boats
Sea Ray Boats
Zodiac Boats
-
Comment