72 Merc 65 hp prop questions

[SHickey]

Hello,

I just mounted a 72 Mercury 65 hp long shaft on my 16' Starcraft Super Sport boat. This is my first Mercury motor experience and I am very excited to get in the water and test it out. The motor came with a 3 blade alum prop that is dinged up. I am in the market for a new prop and I will use the dinged up one as a spare. I like to keep the spare prop in my tool kit if I need to make a repair in an emergency.

I am having a hard time deciding what size new prop I should buy. My boat is pretty light and usually I only have two or at most 3 passengers if I am out on the water. Can someone give me some suggestions as to what works for them given the information I have provided. I do not have a tech on my boat but do have a speedometer. Lastly, do I need a special tool to remove and install the prop??

Thank you in advance for your input.

 

[lovewater]

Re: 72 Merc 65 hp prop questions

Well what i do know is that you do not need any special tool to remove the prop. I know its not much help but its all i got on props lol

 

[merc850]

Re: 72 Merc 65 hp prop questions

I would say that a tach should be your first purchase because the motor is designed for a max. operating range (ie. 4800-5200 rpm) and unless you can measure its rpms you can't match boat and motor.If you have a dealer near you he might let you try different props once you know your rpms. The speed and ride is also affected by the tilt and height of the motor; the motor should be up so that the large plate over the prop is running just under the water at full throttle, that's the height; the boat should ride with the last 1/3 riding on the water, that's the tilt. When you have it setup like that then work on the prop factor.
I set my boat up so that at full throttle it's basically riding on the stern 4" with plenty of air underneath!

 

[SHickey]

Re: 72 Merc 65 hp prop questions

Thank you for your information. I started my motor of the 1st time in my driveway and it fired right up. It had good spray coming out of the water pump and it shifted smoothly into rev and forward. It seemed to be idling at a higher than normal rpm so I may tinker around with the settings and see if I can get it to idle a little slower.

I will definitely look into getting a tech for this motor. I hope they are not too complicated to hook up. Do you have any suggestions?

SH