OMC prop choice

[a91eagletalon]

Boat is a 1976 Reinell with a OMC 190

Question I've had this boat out three times now that I just bought. Right now my max speed is 35 mph at 4500 RPM the prop is a 14x18. The prop is a little beat up and bent I attached pictures. Do you think the prop damage is taking much speed off.

Also do you think I can reprop and get anymore speed out of it. If so what prop size should I go with.

If I stay with the same size prop. Are there different styles of the 14 x 18 or are all the brands the same.

Thanks
Matthew

 

[WesNewell]

Prop looks bent all to heck to me, but I haven't owned an OMC outdrive since about 1983. A new prop certainly wouldn't hurt.

 

[Scott Danforth]

take the prop in to a prop repair shop and get it trued up. that will cause you to loose a good amount of speed

 

[jimmbo]

You're overrevving, provided the tach is accurate. Your engine has a WOT range of 3800 - 4200 rpm. You need to add pitch to get the rpms into that range. Whether you get more speed is unknown. Adding pitch means adding load, resulting in a lower RPM, so there might not be a speed increase. The acceleration will be slower though.

Your motor is known as an Electric Shift Stringer. It hasn't been produced since the latter part of the 70s. Odd that is painted grey. It uses a line of Props that are getting harder to find, though some dealers might have some. You might have to resort to ebay
Here is the prop chart out of an 1981 OMC Accessory cat, so you have an idea of which part #s to look for if you go prop shopping. Click on it, it will open bigger


You must use a specific gear lube in that gearcase. The spec was Type C, but there are some Caveats, Safest Choice is the BRP Premium Blend. 3rd party brands of Type C oil may or may not be compatible with the Electric Shift

 

[a91eagletalon]

You're overrevving, provided the tach is accurate. Your engine has a WOT range of 3800 - 4200 rpm. You need to add pitch to get the rpms into that range. Whether you get more speed is unknown. Adding pitch means adding load, resulting in a lower RPM, so there might not be a speed increase. The acceleration will be slower though.

Your motor is known as an Electric Shift Stringer. It hasn't been produced since the latter part of the 70s. Odd that is painted grey. It uses a line of Props that are getting harder to find, though some dealers might have some. You might have to resort to ebay
Here is the prop chart out of an 1981 OMC Accessory cat, so you have an idea of which part #s to look for if you go prop shopping. Click on it, it will open bigger


You must use a specific gear lube in that gearcase. The spec was Type C, but there are some Caveats, Safest Choice is the BRP Premium Blend. 3rd party brands of Type C oil may or may not be compatible with the Electric Shift

jimmbo thanks for the info

Do you think maybe it is over revving do to the fact the prop is not biting like it should because of the damage.

So the parts numbers in that list are the only props to choose from.

 

[jimmbo]

It might affect the numbers. Which way? It could go either way
Was the prop bent like that before you used it? If not. the numbers you gave were pre or post damage?

Get the prop repaired,or get another 14 X 18, then see what it does, at least you will have a more reliable starting point

Michigan Wheel made some props for those engines too