My CD 25 came with a two stroke Yamaha (estimate about 1995 model) 6 HP short shaft. It was very loud, and could not be turned in the well for help in steering in reverse. My moorage requires backing down a narrow channel about 30 feet wide with frequent wind and current problems.
I replaced the Yamaha with a Nissan 4 stroke 6 HP with an extra long shaft. I especially wanted to get the prop wash down deep enough to the level of the rudder and also to have an included alternator for battery charging. The boat performed much better under power, especially in reverse. To further improve control in reverse, I connected the outboard steering to the rudder through a linkage by temporarily removing the trapezoid plate and connecting to the tiller. Now with the rudder and outboard both controlled by the tiller, steering in reverse was very positive. Once away from the dock the linkage can be disconnected
I had ordered a low pitch prop as appropriate for a 4000 pound displacement boat. The engine came with a standard 8 inch pitch. After being back ordered for over 3 months I found a Mercury 6 inch pitch (part number 48-16144) that fit. Nissan was not very helpful in getting the new prop.
I finally made a test with the 6 inch pitch and found the top speed was abut the same at hull speed of a bit over 5.5 knots. However the boat accelerated much faster and seemed to have better control at low speeds. The Nissan weighs 55 pounds and is not easy to lift out of the well, but I am satisfied with results so far.
I have not yet experienced motoring into a strong headwind, but suspect that the low pitch prop will do much better than standard prop. Especially if the boat is stopped when hitting a bad wave. My past experience was that sails are much better in going to weather in a pounding wave action than an engine.
CD 25 outboard
Moderator: Jim Walsh
Thank You
My boat came with 6HP Nissan have been exploring
new prop pitch was waiting for the winter.I am not sure
what prop I have now , but will take note of your Merc #.
6" Pitch I assum is the lowest we can get?
Tom M
new prop pitch was waiting for the winter.I am not sure
what prop I have now , but will take note of your Merc #.
6" Pitch I assum is the lowest we can get?
Tom M
West Wind
Nissan prop pitch
The original prop has a stamp on the hub "7.8X8"
Nissan confirms that this is a 7.8 inch diameter by 8 inch pitch.
The replacement from Mercury is a 7.9 inch diameter by 6 inch pitch.
The box for the Mercury prop shows a 8 3/8 X 6. Actual diameter measures at about 7.9 inches. It has a cast "6" on one blade.
The slow acceleration with a high pitch is expected. See "Propeller Handbook" by Dave Gerr.
I hope this helps
Nissan confirms that this is a 7.8 inch diameter by 8 inch pitch.
The replacement from Mercury is a 7.9 inch diameter by 6 inch pitch.
The box for the Mercury prop shows a 8 3/8 X 6. Actual diameter measures at about 7.9 inches. It has a cast "6" on one blade.
The slow acceleration with a high pitch is expected. See "Propeller Handbook" by Dave Gerr.
I hope this helps