what size prop for a 65 hp merc and a 30 ft. pontoon?

[staceys old boat]

I bought a 65hp for my toon and don't know where to start. I see 4 blade props at about 80 bucks and I'm thinking of maybe a 12 by 10 pitch? 30 ft. party barge. thanks, Stacey

 

[Bondo]

Re: what size prop for a 65 hp merc and a 30 ft. pontoon?

Ayuh,.... Welcome Aboard,... Not near enough info to work with,....

Please read this first,...

 

[sutor623]

Re: what size prop for a 65 hp merc and a 30 ft. pontoon?

YOu have the 3 cylinder of the 4 cylinder motor? Mine had the wrong lower unit on it so the gear ratio messed me all up.

 

[staceys old boat]

Re: what size prop for a 65 hp merc and a 30 ft. pontoon?

Hi, I had already read the sticky. 1975 65 merc. long shaft. 30ft. partybarge. Not looking for speed but I know Idon't want an over rever either. just thought someone out there might have a good place to start. The motor is new to the boat with no prop yet. Old motor is a 175 blackmax with a 10.5 by 13 and the toon reaches speeds of 30mph but sucks 25 gallons per 2 hours pulling atube for the kids. Those days are over. Just looking to putt around and enjoy now.

 

[jestor68]

Re: what size prop for a 65 hp merc and a 30 ft. pontoon?

The 1975 Merc 650 is a three cylinder motor. I would start with a 8" pitch 4 blade prop.

The Mercury prop selector says to expect about 16 mph at about 5200 rpm given the size and weight of your pontoon boat.

Your recommended rpm range is 4800-5300.