OMC 400 sterndrive with 15 spline prop shaft

[Buzzsaw420]

Hi all I’ve tried to look up my question before posting because I usually can find the answer here. I read that the 400 series is a 13 spline and the 800 a 15 spline. My boat is 1979 17’ Peterborough Fiberglass bowrider, 2.5 120hp model 990243S1 in-line 4. 400 sterndrive model 981871. I have the OMC parts so I ordered a prop, and after taking off my old one see that it has 15 splines. So back goes the prop and my question is am I missing something or is there a reason it is like this. Thanks in advance, Mark.

 

[Buzzsaw420]

Hi all I’ve tried to look up my question before posting because I usually can find the answer here. I read that the 400 series is a 13 spline and the 800 a 15 spline. My boat is 1979 17’ Peterborough Fiberglass bowrider, 2.5 120hp model 990243S1 in-line 4. 400 sterndrive model 981871. I have the OMC parts book so I ordered a prop, and after taking off my old one see that it has 15 splines. So back goes the prop and my question is am I missing something or is there a reason it is like this. Thanks in advance, Mark.

 

[kenny nunez]

I have never tried it but it is possible to mate a 800 lower to a 400 upper. How did your boat perform in relation to rpm? Does it turn up to 4000- 4400 ?

 

[Buzzsaw420]

I have never tried it but it is possible to mate a 800 lower to a 400 upper. How did your boat perform in relation to rpm? Does it turn up to 4000- 4400 ?

I know that my tach is not working right it would max out at about 3200 and fishfinder says 24 mph motor is running nice but not giving max rpm. Select trim is stuck in the up position so I’m on plane in a heartbeat. The pro is a 3 blade aluminium 15x17.

 

[kenny nunez]

Try to get the power trim repaired. And of course the tachometer.

 

[Buzzsaw420]

Try to get the power trim repaired. And of course the tachometer.

Yes, two of my many winter projects. I have heard that a prop like a 15x13 would also give me higher rpms and faster top speed. I won’t be pulling skiers or boarders so I’m not worried about the hole shot. Thanks Kenny for the info, just my luck to get a hybrid.

 

[Buzzsaw420]

Does this mean I’m looking for a prop under the 800 stern drives with the lowest horsepower, pre 1990? Thanks

 

[kenny nunez]

The main thing you have to know is what is the maximum rpm, then you will know which propeller you need.

 

[Buzzsaw420]

Roger that, I will be fixing the tach but will run it on the meter to see what rpm I will get. For service reasons should I be looking for a omc sterndrive 800 series parts catalog for the bottom end?

 

[racerone]

The 60E would make it a Bracebridge area boat.-------If it planes quickly you do not need a 13" pitch prop !!------evinrudeparts.ca----In your area can help you.

 

[Buzzsaw420]

The 60E would make it a Bracebridge area boat.-------If it planes quickly you do not need a 13" pitch prop !!------evinrudeparts.ca----In your area can help you.

I’m in southern Ontario so not far(4 hours) yes it does plane quick, excellent again thanks for the link racerone. I thought I just got to know this boat and find out it has a Frankenstein outdrive. Thanks again guys for your help.