what size prop shaft do I have?

[Marioleonard]

I have a 1974 115hp evinrude. I have my manual on the way but I have a really good deal on a prop if they fit. I need to know what size my prop shaft is? thanks for the help guys.

 

[emdsapmgr]

Re: what size prop shat do I have?

Re: what size prop shat do I have?

It's unusual to ask for the propshaft size. Usually the props are sold by their size stamped on the hub/side (ie: 13 X 17) and with 13 splines.

 

[Marioleonard]

Re: what size prop shat do I have?

Re: what size prop shat do I have?

so mines has 13 splines? I dont know that guy posted them on craiglist and said that some fit 3/4 inch shaft and others have 1 inch shaft?

 

[emdsapmgr]

Re: what size prop shat do I have?

Re: what size prop shat do I have?

Whenever you go to purchase a prop, you really need to know what specific prop you want. That means you have run the engine and know what pitch is best for your boat/engine setup. That means you know the pitch you need, whether aluminum or stanless steel, and the number of blades you want (either 3 or 4). I'd contact the seller and ask him for some details.

 

[SparkieBoat]

Re: what size prop shat do I have?

Re: what size prop shat do I have?

Not only do you need a prop that fits your shaft..the pitch and diameter also are important, you can determine the diameter tolerances of your motor here.
http://boatpropellers.iboats.com/?*******=237755012&**********=589906055
now if you get the wrong pitch you can also damage your motor or lose performance or both...you need to determine the pitch of your current prop if possible..many times the numbers are near the center hole, so you may have to remove it to find the numbers..sometimes they are not legible...this can be a big problem..then you need to borrow a prop from a friend that has a known pitch and see what RPMs and speed you get at WOT, also if you can get a total weight on your boat, and what kind of boat would help also..with this information we can figure the pitch best for your boat. I would recommend just getting a brand new one from the link provided, the have the Apollo ones for around $200..they are great props. I have had 2 of them.

 

[ezeke]

Re: what size prop shat do I have?

Re: what size prop shat do I have?

The 1974 standard gearcase came with a 13 spline propeller shaft that had a diameter of 8/10" on the portion of the shaft between the splines and the thrust bushing. The threaded portion of the shaft may be 3/4".

The propeller forum on this site will be better suited for helping with your particular setup needs.

The OE propellers that are suitable will have part numbers stamped on the hubs.

 

[Marioleonard]

Re: what size prop shat do I have?

Re: what size prop shat do I have?

does anyone know what the demisions on the oem prop that came with it are? I dont have a prop with it. It dident come with one when I pick it up? I am lost for what I need?

 

[ezeke]

Re: what size prop shat do I have?

Re: what size prop shat do I have?

Go to the parts catalog for your specific motor, then to the gearcase diagram. You will find the OE list of original propellers sold with the motor and their sizes within the parts list. By clicking the magnifying glass icon on the part number you can see the superseding part number if any. http://shop.evinrude.com/

 

[SparkieBoat]

Re: what size prop shat do I have?

Re: what size prop shat do I have?

you need a prop...no need to be lost. you need to borrow a prop if you can..a outboard repair shop should have one they could lend you, maybe they would require a deposit if they do not know you. Or you could just guess at what pitch you think you need, which could get costly because you will probably not guess right and need to buy another prop.

 

[emdsapmgr]

Re: what size prop shat do I have?

Re: what size prop shat do I have?

The early OMC engines did come with a standard prop from the factory. (This practice has long since been discontinued on newer engines.) Yours probably came with an aluminum 13 1/4" X 17" 3 blade prop. That prop was considered an "all-purpose" prop by the factory. If you are looking to buy your first prop that is a good pitch to start with. The original props have been superceded over the years, so don't get hung up on the original part number or the diameter of the prop. Just ask for an alumuminum 17 pitch for your engine. When you install the prop, you want the engine to run on plane at 5500 rpm at full throttle. If the engine does not run within a few hundred rpm of that, you will need to get another pitch prop that will let the engine run at that top end rpm. You can keep the first prop as a spare.

 

[SparkieBoat]

Re: what size prop shaft do I have?

they also have graphite props for around $90...might be a cheaper way of figuring out the pitch you need. What size boat do you have??? If it is a bass style boat or a real light boat with little draft I would start with a 19 pitch prop...if it is a heavier or deep V style boat the 17 will be a better start. Cheaper still though if you can find one to borrow.

 

[ezeke]

Re: what size prop shaft do I have?

iboats sells a Solas aluminum 3 blade for around $90. I have used them and find them good for all around use. The 17 pitch is #2411-133-17

http://www.iboats.com/Solas-Amita-3...****.997749779--view_id.477755--viewcart.long

Michigan Wheel's Michigan Match #011083 is around $100.

http://www.powercatboat.com/brochure/1973/1973_pg2.jpg

 

[Marioleonard]

Re: what size prop shaft do I have?

hey how did you know that I had a powercat? and were did you find that mag? I am part of the yahoo group for power cats.

 

[Marioleonard]

Re: what size prop shaft do I have?

I have a 15t powercat. It is a tri-hull boat and it is really only 14 ft 6in.

 

[ezeke]

Re: what size prop shaft do I have?

hey how did you know that I had a powercat? and were did you find that mag? I am part of the yahoo group for power cats.

It's on your public profile: http://forums.iboats.com/member.php?u=152773

 

[SparkieBoat]

Re: what size prop shaft do I have?

you may end up with a 21 pitch prop on that boat if it is not very heavy. You want at least 5500 RPM at wide open Throttle ( WOT ) but no more than around 6000....5800 is about right...you change approximately 200 RPMs per inch in pitch change...if you go from a 19 pitch to a 17 pitch it would potentially raise your WOT RPMs from 5500 to 5900..this is a general rule of thumb. the lower pitch range for your boat will be better for skiing and tubing..so you would want a slightly higher WOT RPM like around 6000 or so..also if you tend to over load your boat you would want the same thing..but if you run light and do mostly just fishing a slightly higher pitch would be better for you with a WOT around 5600-5800 RPMs..these are just all approximates, as you experiment with different props you will find whats best for your needs. This is why you need lots of Boat friends so you can borrow their props and see what pitch is best for you.