OMC Stringer 800 ---> 400 interchangable?

[Desyfering1]

HI guys, happy new boating season to those who live in seasonal weather like me.

My 84 15? OMC I/O 2.5L 4-cyl. had water get into the stern late last season and seized up the bearings in the upper gearcase seized up. The gears look okay.

I located a used OMC 800 Stern drive that came off a 5.0 L V8 boat, I purchased it for a very reasonable price, much cheaper than even buying a set of new bearings. I have been told I can bolt the 800 right on up as the cases are the same. I just need to take the drive shaft out of the 400 and use it for the 800. Besides having to wire it for electronic shift, as the 400 is cable do I also need to change the prop?

Given the gear ratio change, will I need to change the prop with a different pitch to help bring the boat out to plane?

What can I expect if I just switched up the drives and ran it on my 4-cylinder 2.5L?

Am I better to strip the parts from the 800 and rebuild my 400 to spec with the 800?s parts?

Or should I keep it simple and just bolt up the 800 to the 2.5L and look at switching props? I do not know what pitch is on the prop on the 800

Anyone have experience doing this before?



Thanks for the advice as always

 

[Howard Sterndrive]

Re: OMC Stringer 800 ---> 400 interchangable?

Besides having to wire it for electronic shift, as the 400 is cable

The drive you bought is electric shift? That's technically not an 800. It's just an OMC electric shift sterndrive from a V8.

I doubt you have anything you can use on your 2.5L

If you supply clear pics of the drive, and model numbers, we can tell you if the upper gearing is even similar....

If the electric shift drive is low profile, the upper gearcase might be of some value to you if it has trucourse steering (most V8 electric shift drives were high profile, and many lacked trucourse)...

To make the whole drive work, you'd have to source an electric shift control, (rare to find one with a good switch in it) then you could possibly make it work but the gear ratios are probably not close enough for success.

If you bought it cheap, you can maybe sell it for a profit and use the $ to fix your drive

 

[Desyfering1]

Re: OMC Stringer 800 ---> 400 interchangable?

Okay I guess it's not an 800, it's an electric shift OMC drive.

The bearings are exactly the same though.

I can strip the bearings from the drive I bought and put it in my 2.5L.

To my understanding, if I swapped drives, I would just need to change the pitch on the prop no? WHat would happen if I just swapped drives?

Thanks

 

[Bondo]

Re: OMC Stringer 800 ---> 400 interchangable?

WHat would happen if I just swapped drives?

Ayuh,... You be Up-dating Backwards....

 

[Howard Sterndrive]

Re: OMC Stringer 800 ---> 400 interchangable?

Okay I guess it's not an 800, it's an electric shift OMC drive.

The bearings are exactly the same though.

I can strip the bearings from the drive I bought and put it in my 2.5L.

Tapered roller bearing cups are pressed in, and are usually destroyed during their removal from the housing.
Seems a waste to sacrifice a whole drive for bearings that you could get for $75 or so new.

To my understanding, if I swapped drives, I would just need to change the pitch on the prop no? WHat would happen if I just swapped drives?

If you stuck a high profile V8 drive where a 400 series used to be, I suppose the boat would putt along at idle ok.
If you ever mustered enough torque to to turn your new 11P(?) prop fast enough to get on plane, I suppose the nose of the boat might submarine and sink.
I dunno, I've never tried lowering the vent plate of an i/o 4 inches below the keel...
I gotta imagine steering it would be somewhat scary.

Of course, we still don't know if the drive you bought even has steering parts in it.