What prop size for my new propeller?

justinismach

Recruit
Joined
Apr 20, 2017
Messages
3
Hey guys!
So i recently bought a 2004 Tahoe Q4 and love it, but one of the props got a little nick and i feel it would be best to replace it, a guy sells them for $90 refurbished and almost brand new and has several instock. Only thing is I dont know what size to get?? He sold me a 15 1/4 x 15 prop but it hit the anode. After reading up on it im not sure if thats the best size prop? I would like a good prop size for performance and planing easily. I got a Mercruiser 3.0 and the Alpha One 2.0 in it. I would tell you what prop i got now but that one is corroded and i cant even read the numbers on it. If the 15 1/4 works, should i sand down the anode? Im not sure if i got power steering, nor do i know how to check? I heard if i got PS I can grind the anode down, which would fix the fact that id need to go exchange new propellers.
Also, forgot to raise lower unit when towing out and scraped skeg a bit, theres like 1/3 left, but I heard good and bad about skeg guards- let it be or fix it? I learned my lesson and wont let it happen haha. Thanks so much guys and what a pleasure to be on here.
 

jimmbo

Supreme Mariner
Joined
May 24, 2004
Messages
12,944
Welcome aboard

http://forums.iboats.com/forum/gene...p-questions-and-topics/295058-read-this-first

What was your current prop, and what rpms were you getting a WOT?

You can buy a variety of trim tab/anodes that have more clearance, or are just flat plates.
Rebuilt props are rarely Almost Brand New. Most were probably worse than yours. The again if your skeg is 2/3 gone, you prop can't be in very good shape.
Your skeg... 1/3 left, must have been a heck of 'a bit of a scrape'. Most prop repair places can weld a new skeg on. As for those slip and bolt on guards, I think they are waste, that's my opinion of them
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,286
Jeez....sounds like the dealer was trying to rid himself of a prop.
Would be pretty confident that a 15x15 isn't ideal for your boat.
The local dealer here flogs off 16x16 props to guys with 24-30ft bayliner and similar with 5.7's. To decent effect, in that they seem ideal to get big heavy boats with lots of weight aft up onto the plane. Not speed machines though.
I'd imagine that you would be looking for a 14x19, 14x21 or similar, depending on your specs. Speed, gear ratio and rpms. As mentioned above, really need those before making an educated call on it.
 

justinismach

Recruit
Joined
Apr 20, 2017
Messages
3
Wow thanks, yeah i do believe also- im going to go exchange it tomorrow- ideally for my boat I believe I want a 14x19 stainless 4 blade prop? Or is the 14x19 for the 3 blade, i heard something about changing pitch based on the 4 or 3 blades? Let me know yall`s thoughts on my ideal prop? And if i really need a 4 blade or a 3. Im almost set on stainless
 

Lowlysubaruguy

Chief Petty Officer
Joined
Dec 3, 2012
Messages
514
Im betting a 14.5x19 will be on the edge of to much prop for a 3.0 mercruiser in a 20 foot boat. You might find th 4 blade is ok as top speed is a little lower and the power on take off is usually a little better especially loaded or in rough water . see if yo cant test a 14.5x 17 as well before you buy. Then after you find the right size think anout higher end SS props they tend to give overall performance that aluminum props cant match.

For most IB uses 4 blade props dont usually ad much unless your heavy and in rough water. You always loose top speed with them better to match the right three blade prop
 
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