65hp 650 merc

[fshnne1]

I have an older merc 65hp 650 Kiekhaefer, i Do alot of fishing and some wake boarding, skiing, and tube pulling, sorry I know this is asked alot! what would be the best prop pitch etc...?

 

[fshnne1]

Re: 65hp 650 merc

sorry it is on a 15 foot 68 larson fiberglass v hull currently has a I think original two blade brass prop, looking for best performance hole shot and max speed

 

[cougar1985]

Re: 65hp 650 merc

i just got rid of a 1965 65 hp. i had a similar boat and i used a 15p prop if i remember correctly. i will go out to the garage and see if i can dig it up and check. i think i have 3 or so props hanging around. i will get back after i check and let you know what i find out about what i used.

 

[fshnne1]

Re: 65hp 650 merc

cougar thanks contact me by email if you want to get rid of them peterbsanderson@hotmail.com

 

[cougar1985]

Re: 65hp 650 merc

i found 3 props that came off my merc. your 650 had the large gear case correct? 4 cylinder.? i cant see the pitchs on the props. im having a hard time figuring out the pitches as the numbers are not very legible.

 

[fshnne1]

Re: 65hp 650 merc

thats the one

 

[Texasmark]

Re: 65hp 650 merc

Hey Fishin:<br /><br />You are asking for everything and you can't get it. You have to compromise.<br /><br />The fewer the blades (I've learned from Merc) the higher the effeciency, but only on light fast boats, and the higher the prop vibration. <br /><br />When you start talking about tubing and skiing and all you need more metal in the water; more blades, less pitch....like 3 or 4 blades.<br /><br />For the real answer as to what works, you just have to run it. Everything else is just gossip.<br /><br />Mark

 

[fshnne1]

Re: 65hp 650 merc

going to a 3 or four blade with less pitch would be better for hole shot, would it be just best to leave my two blade on I run about 32 mph with two full size adults and fishing gear at about 5000 rpms the only problem I have is the two blade will yank my wife right out of the water shes about 120 lbs but when I try to get back there it struggles @ 180 lbs

 

[cougar1985]

Re: 65hp 650 merc

your asking for a lot as you will never go from 32 mph to 55 no mattter what prop you use,peter. i would expect a modest improvement in speed maybe 5mph. i went from a 17p to a 19 p on my boat with a 90 rude and gained 5.9 mph by gps. at the most. in the mid 30,s is still fast for a old boat and motor and nothing to laugh at concidering everthing.im with texasmark on this one as you cant have everything,and must chose what you would be most happy with .

 

[rickdb1boat]

Re: 65hp 650 merc

Or have 2 props. One for pulling skiers and tubes and one for cruising....Love those old 650's....I'd get a 3 blade on there and drop some pitch and it should jerk you out of the water toot sweet. I think my old 67' 650 I had on my 16' Wellcraft had a 15" pitch and it worked real well. Not to say that it would be right for your set-up. You need to find your WOT RPM's and go from there...

 

[PuckHog]

Re: 65hp 650 merc

I had a '69 Merc 650 on a 15' '69 Glastron open bow tri-hull. My prop was a 12-1/4" x 15 pitch 3 blade aluminum (by Mercury) and I had no problem pulling a 200 lb. skier right up out of the water. The only speed data I have was 4 adults with a bunch of stuff I could go 30.5 mph by GPS. It was pretty conservative on gas as well. During a whole day of boating I rarely used both 6 gal. cans of gas.