prop selection

[Jim McMurray]

My 1975 hunter 30 has a yanmar 12hp. diesel, I have heard that changing the prop from the stock 2 blade to a three blade will give me better speed/thrust characteristics. Is this so? If yes, what is the size prop recommended?TnxJim

 

[Bill Boyke]

How accurate is the inital prop pitch suggestions?

I am hoping to get my own '75 Hunter 30 in the water this year. 33rd hull, keel/centerboarder. I have called Max Prop and they gave me some inital values. (I don't recall them off hand).I intend to get a 3 bladed Max in a year or 2. I am primarily a crusier with hopes to run the bouys occasionally.My hope is to not have to adjust the pitch more than once a season if I have to. How accurate is Max Props inital suggestions?Bill Boyke

 

[Kevin L. Woody]

Recommended prop.

Dear Jim:Thank you for your letter.If the current two blade is not set correctly, you may see additional speed when you convert to the three blade. If the two blade is set correctly that speed increase will only happen when the vessel is confronted with additional strain on the vessel like maneuvering, stopping and accelerating, heaving winds or seas and possibly towing something. The three blade will also help to reduce noise and any vibrations which are a result of the two. The recommended three blade will depend on your current drive train combination, (for any one else reading this note with a Hunter 30) so with the 1GM 12, your recommended three blade is a 13” diameter with 8” of pitch. If you should have any other questions please do not hesitate in asking. Sincerely, Kevin L. Woody

 

[Bill Boyke]

Max-prop Recommendations

Maxprops recomendations on a '75 Hunter 30 with a YSE12 diesel is a 13X8 3blade prop.The angle to install to was suggested at 18 degrees.Part numbers required are 63-313 and 63-100.313 means 3 blade 13 inches.100 means 1 inch prop shaft.63 means 63 mm.MSRP is $1980 but you can get it for less.Bill Boyke