Changing OMC 800 4.3L outdrive to a 5.0L outdrive

[scottkanderson]

My OMC stringer outdrive is about to go, lots of water in the gear oil. I have a 4.3L engine with a 1.68 gear ratio in the drive. Can I put a 5.0L drive with a 1.50 gear ratio or will this bog the engine down to much. Right now it runs WOT at 4600.<br /><br />I want to do this, because I can get a rebuilt drive at a good price. There is nowhere within 300 miles to have mine rebuilt.<br /><br />Just wondering how much of an effect this gear ratio will have.<br /><br />Thanks

 

[scottkanderson]

Re: Changing OMC 800 4.3L outdrive to a 5.0L outdrive

Oh, and they are both 1985 so I know it will fit, if this helps

 

[whywhyzed]

Re: Changing OMC 800 4.3L outdrive to a 5.0L outdrive

What altitude are you at?<br />If you are up where the air is thin, I wouldn't ...<br />Otherwise, I think you would get away with it if you went down in prop pitch by 2"

 

[scottkanderson]

Re: Changing OMC 800 4.3L outdrive to a 5.0L outdrive

Bummer, I'm at 7,500 ft and already running a 15 pitch.

 

[Boomyal]

Re: Changing OMC 800 4.3L outdrive to a 5.0L outdrive

If you want to talk to an OMC guru in Portland OR, let me know. This guy gets outdrives shipped in from all over the country. He knows them like the back of his hand.

 

[scottkanderson]

Re: Changing OMC 800 4.3L outdrive to a 5.0L outdrive

Thanks Boomyal, how can I get hold of him?

 

[Boomyal]

Re: Changing OMC 800 4.3L outdrive to a 5.0L outdrive

Originally posted by telluride:<br /> Thanks Boomyal, how can I get hold of him?

Steve Ryan @ Ryans Marine-503 282 8807<br /><br />If there are any tricks or mods, he knows them and he'll do it.<br /><br />Don't know if there are any for the full mechanical but there are a couple for the hydro-mechanical.

 

[whywhyzed]

Re: Changing OMC 800 4.3L outdrive to a 5.0L outdrive

p.s. the lower units all have the same ratio in 800 series, so if your upper is good you could swap lowers...

 

[scottkanderson]

Re: Changing OMC 800 4.3L outdrive to a 5.0L outdrive

yeah I know, but there was 3 or 4 oz of water in there too. No metal chips though. How hard would it be for me to change out the gears? I have no special tools. I do have the books. I mean what if I put in just the 19 gear from the 21/19 ratio into the spot of the the the 17 on the 21/17 ratio. Can this be done, and if so, how hard would it be. Or would I have to change out all of the gears?

 

[KaGee]

Re: Changing OMC 800 4.3L outdrive to a 5.0L outdrive

Resealing both units is not a huge deal. If water is all you have, send him the drive and have it resealed.

 

[cobra 3.0]

Re: Changing OMC 800 4.3L outdrive to a 5.0L outdrive

Yeah my thoughts exactly! Why change drives if all you need is new seals? Unless you have costed both alternatives and changing costs you way less? However, remember you may be no further ahead if you find out that your swap brings you a drive with worn gears.<br /><br />On my OMC Cobra drive I had a small crack in the nose cone from hitting a rock. I couldn't see it with the naked eye, but once the mechanic opened it up, it was more than visible from the inside. A crack like that is easily welded from the front by a prop fixer guy. So it may not even be your seals, but it's always a good ideas to change them out anyways when it's all apart.<br /><br />You may also want to try to look at it yourself first if you have a good mechanical ability. Tools are usually available on ebay and you can resell them once you're done with them.