Prop???

C YENSEN · #1 02-07-2006, 02:41 PM

sorry i have been away a while fellas but just too swamped at work. i am still working on the map when i have a second of spare time.

the shop that worked on my boat said i had the wrong prop and the motor was over-revving.

i have an '84 I/O mercruiser 470 (160 hp)

anyone know what prop i should have on this thing? ???

thanks

Blue_Runner · #2 02-08-2006, 12:14 PM

Cy if you can post the current prop size, it might help explain the problem. Should be printed on the prop somewhere. Look on the end where the nut holds it on or on the side.

macojoe · #3 02-08-2006, 12:32 PM

you would think a good shop could have steered you in the direction of the right size prop!!

When mine was a I/O (165 hp Chevy 250) I had a 15 1/4 X 15

when I switched to O/B I was told to go to a 17 pitch. It pushed the boat fine but I still felt that it was wrong. I bought another 15 1/4 X 15 and i love the all around performance.

Of coarse this is what worked for me. and you may like something different.

A good prop shop can tell you what you need over the phone to with in one size.
They just need boat length, weight, make, and HP. My shop even let me take a prop try it and said as long as I didn't hit anything i could swap it.

:-*

C YENSEN · #4 02-08-2006, 12:48 PM

they are looking for a new prop for me, i was just wondering when they tell me what they were putting on it i would know if it was right.

macojoe · #5 02-08-2006, 02:04 PM

Well ask them if you can try it. And if its is not the right one will they take it back!

I think most people here have a 17 pitch.

theres no real way to say for sure if its the right prop till you get on the water.
This way you can feel it take off out the hole and then see what the top end is. Make sure you tac is working well as this is how you are going to tell if you are over or under reving.

#6 02-09-2006, 10:35 PM

Cy,

On the valve cover of your engine, there should be a label that has the model, hp, spark plug etc. Also on that label is the wide open throttle operating range. Whatever prop you choose should put you in that range when you run W.O.T. You should try to get it on the high side of the range, which will allow you to put weight in the boat (passengers, fuel coolers etc.) and still remain in that range. If it falls below that range, you will tulip an exhaust valve. If it is above, over-revving damae will result.
Everyone is right in this forum, the only way you know for sure is to try the prop. This cannot be done over the phone. Anyone that gets it right on the phone made a good guess.
Good Luck....Hope that helped

reelapeelin · #7 02-10-2006, 08:41 AM

Cyensen, these guys can spec your boat and tell ya ZACKLY which prop will work best...takes all the guesswork out of it

http://www.ptprop.com/PTRegistration.html

They are great to work with...very customer oriented... ;) ;D...

C YENSEN · #8 02-10-2006, 07:25 PM

thanks fellas ;D