**** Propellers ***** ??????

[Clembone]

I was trying to find a new prop for my 1973 Merc 85hp. What type should I buy? I have the original 2 blade and a worn out 3 blade. I saw 3 and 4 blade props for my Merc. Any suggestions on make/model and additional parts needed would be greatly appreciated.

 

[05GlastronSX]

Re: **** Propellers ***** ??????

what are you looking for performance wise? top end, acceleration...ect there are so many things to concider when selecting a new prop. first, you need to have a tach so that when you do test your props, you will know if you are in the correct WOT rpm range or not. second, you need to find out what pitch the 2 and 3 blade props are so you atleast have a general idea of the pitch you are looking for. you will most likly not use a 2 blade, so the 3 blade would be best. third, how much are you looking to spend? you can get props anywhere from 120 dollars to 400-500 dollars. also, are you looking for aluminum or SS. you need to give us the most info you can in order for any of us to be able to give our suggestions on helping you find the right prop for your boat.

 

[Clembone]

Re: **** Propellers ***** ??????

I guess there is much more to props than I thought. My tach reads 5000 rpm when I am running wot. I do not know if this is what the motor is spec'ed for. The motor is a 1973 Mercury 85hp. Can you help me out with few questions?<br /><br />

1. <br />
2. How do you measure pitch?<br />
3. What should the RPMs be for my motor?<br />
4. Can I use the prop finder on this site to find a suitable replacement?<br />

<br /> <br />Thanks,

 

[Clembone]

Re: **** Propellers ***** ??????

Oh and lastly. I was looking to spend 200 or less.

 

[Clembone]

Re: **** Propellers ***** ??????

Oh and the boat is a 1974 allglass trihull 16ft flat bottom.

 

[05GlastronSX]

Re: **** Propellers ***** ??????

read up on this and it will explain all about propeller pitch.<br />about propeller pitch<br />Since your looking to spend under 200, you will be most likly looking for an aluminum prop. for 200 dollars you can get a very good aluminum prop that should satisfy your needs. im not sure about the WOT rpms for the engine, but 5000 seems to be alittle low. i bet the rpms for that engine are in the mid 5000's(not sure though). and to answer your last question, you can use this site to find a suitable replacement propeller. find out what pitch you need and youll be set.

 

[Clembone]

Re: **** Propellers ***** ??????

I read up and understand for the most part the importance of the correct prop. I called around and got little knowledge from the local marinas as to how to go about measuring pitch. One went as far as to say you can’t. Well if you can’t then how do they produce them? Real winners as you can see. I did find on the internet how it is done and saw pictures of the tool used to do it. One marina said "What type of motor and boat do you have?" After I told him he stated "You need a 13 1/4 X 21. Where does one go to get a prop measured? Any guidance at this point would be nice as I am beginning to think this quest is pointless. It is amazing the amount of misinformation told to consumers. Thank goodness for the internet.

 

[Dhadley]

Re: **** Propellers ***** ??????

I dont know of any dealer who has a pitch gauge but I'm sure some do. Even with the right tools it may be confusing because of variable pitch. You have to know where each manufacturer measures their props. There is a standard but I'm not sure all manufacturers follow it. <br /><br />Any prop shop can quickly measure it for you. The correct prop for your rig depends on the set up, hull design and intended use.

 

[Moody Blue]

Re: **** Propellers ***** ??????

I have a shop near me that specializes only in props. He has a pitch gauge and helped me find the pitch on a prop that had NO identifying numbers on it. They do exist. As a start, measure the diameter of your existing prop and go from there. Make sure you count the number of splines on the prop shaft because you can buy the same prop configuration (diam/pitch) with different spline counts. <br />Talk with a local dealer and see if they would be willing to let you 'try before you buy' to find just the right prop. Some will be very helpful that way, other won't.

 

[Clembone]

Re: **** Propellers ***** ??????

Ahhh, sometimes you have to dig in. Found a prop shop in the good old telephone book. Nothing like low tech to get the job done. It was refreshing to speak with a knowledgeable person. He stated that the prop should have it stamped on the side for those of you like me that did not know that. Of course I did not think to check the prop itself. I am a new to the leisure boat industry. I did server our country in the Navy though and I'm a shellback to boot!

 

[Clembone]

Re: **** Propellers ***** ??????

Oh one last thing. Here is a great place to get genral prop information.<br /><br /> http://www.marine-outboards.com/choosing-propeller.htm

 

[Clembone]

Re: **** Propellers ***** ??????

Thanks