I want to buy a new prop?

[drrm123]

I have a 1981 beachcraft 17ft boat with a string 800 and 3.8 litre omc engine how can I find out what prop came stock on this boat? There is one on boat now but not sure of pitch. Not sure of what pitch to use from numerous props for sale?

 

[Silvertip]

Re: I want to buy a new prop?

There is no such thing as a "stock prop". In the case of I/O's the manufacturer may have stuck a prop on the boat but they have no idea what the load is going to be, how the owner uses the boat, whether it will tow water toys, etc so that prop very likely is a guess at best. Go here:

http://www.boat-props.com/propellers/s#sterndrive

Enter OMC and the year in the "Sterndrive Props" box and you will be given a list of engines and outdrives. Pick yours and you'll be given a list of props of various pitches.

Check your prop hub between the blades for a part number or numbers like this: 15 x 17 (15 inches diameter -- 17 pitch). If you see neither a part number or pitch, remove the mounting hardware and check the face of the hub.

Lastly, without any wide open throttle rpm data you can't begin to select the proper prop unless you simply want an exact duplicate of what you have. In the end, that may or may not be the best prop.

 

[steelespike]

Re: I want to buy a new prop?

I think you will be better off finding out what prop you have now Numbers may be in plain sight near the base of the blades on the outside of the hub numbers may be on the inner hub as well.If you give us those numbers and your present wot(wide open throttle)speed and rpm.Wouldn't hurt to give us the hp of the 3.8 motor.Also your typical load and activities.Is the prop in good shape?

 

[drrm123]

Re: I want to buy a new prop?

I haven't put the boat in the water yet. Bought it used about 3 weeks ago and have been repairing minor problems and wanted to have all safety equipment before going out and also waiting for someone else to go out at the same time just in case I have to be towed back in. I'll check the prop for part number it has minor damage and wanted to buy a new one but will wait and check the speed of boat and rpm it operates at to give more info when I'm ready. Will try to get in water on sunday the river near my house is to low and will take to lake about 20 miles away.

 

[drrm123]

Re: I want to buy a new prop?

Finally put boat in water today. The max rpm I get is about 2100 to 2200 at about 35 mph. With throttle wide open is the prop slipping or what can my problem be, not sure if pitch on prop is too much 15X17 this is a prop with some damage on the edge I can post a picture if necessary. Service manual says this engine should have rull throttle operating range of 4000-4400rpm.