1990 OMC 4.3L Equivalent and Swap Complexity???

[genuinegemini]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

Just so you know, the drive needs to come off to take out the engine.

Okay. Good to know. I am going to go over the manual that Four Winns, turned me on to. Hopefully it will have what I need to get started with the removal process. Does the drive need to be up or down, or does it matter?

 

[bruceb58]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

You have to remove the trim rams first and it is easier to do that if they are down but you can take them off in any position. Once you take them off, the drive will obviously go to its furthest down position.

 

[genuinegemini]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

You have to remove the trim rams first and it is easier to do that if they are down but you can take them off in any position. Once you take them off, the drive will obviously go to its furthest down position.

Do I need to build a craddle or support for it? It looks like it's about 300lbs. Also, in the video I watched, the guy had turned the drive upside down and it looked like he had a time getting the lower unit off. Do I need to rig a device like that, or can the be worked on, on a bench-top? I just want to make sure I do it right and safely. Thanks for your input, Bruce. It really helps a lot.

 

[bruceb58]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

Its probably around 80 lbs. I have a stand for mine but it isn't necessary for just taking it on and off. The stand helps if you are by yourself. I can pull and replace my Volvo Duoprop all by myself with it.

 

[genuinegemini]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

Its probably around 80 lbs. I have a stand for mine but it isn't necessary for just taking it on and off. The stand helps if you are by yourself. I can pull and replace my Volvo Duoprop all by myself with it.

Well that makes me feel a lot better. I'll get crackin on that manual tonight, and hopefully be able to pull the outdrive tomorrow. I am by myself, so I will probably build a craddle. Thanks, Bruce. I'll let ya know how it goes. Is there anything special I should know other than have it in nuetral and supported? Anything not metioned in the manual?

 

[bruceb58]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

It may be fun getting it to slide off if it hasn't been removed in quite awhile.

 

[genuinegemini]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

It may be fun getting it slide off if it hasn't been removed in quite awhile.

I am certain that will be the case...:facepalm: It ain't been registered in six, so.....

 

[genuinegemini]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

Hey fellas, what's the deal with the trim rams? I can't get them to come off the pins. Am I missing something or am I just not using enough force. I don't want to bend or break anything. The manual that Four Winns turned me on to, doesn't really show the detail of getting them off, only how to rebuild them. I can get the shaft connector to move about an 1/8" or so, but it seems like it's tweaking or stressing the cylinder rods. Any insight to what I may be doing wrong?


It seems like the port-side pin is trying to come off with the ram, instead of the ram coming off the pin. Is that normal?

 

[Bondo]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

It seems like the port-side pin is trying to come off with the ram, instead of the ram coming off the pin. Is that normal?

Ayuh,.... Drive the pin, Out.....either way....

 

[genuinegemini]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

Ayuh,.... Drive the pin, Out.....either way....

Thanks, Bond-o! Outdrive removal success!.... The pins were a little tough, but the outdrice came off with no issues. The gear oil looked "clumpy", but it was all soft and I didn't notice any shavinges or metal flake appearance in th lube. Lot's of calcium build up in the cooling ports. I'm thinking C/L/R or similar? Given how easy the outdrive came off, I'm taking it as a sign of good things.

Now that the outdrive is off, what's the next step? Can I disconnect the accessories and pull the engine, or do I still have work on the gimble and transom mount? Sorry for the "101" questions. I'm just waiting on the funds to get my manual and then I won't have to bother with such trivial questions. Thanks again for all the guidence, fellas.

 

[bruceb58]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

Now you can pull the engine once you disconnect the exhaust, cooling hoses, throttle/shift cables and unplug the wiring harness.

 

[genuinegemini]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

Now you can pull the engine once you disconnect the exhaust, cooling hoses, throttle/shift cables and unplug the wiring harness.

Excellent! I'm going to go start that right now. Thanks a million, guys! I feel like (what could've been) a huge hurdle has been cleared. I kept reading all these horror stories about come alongs, trees and trucks vs. outdrive. I'm so glad it was as easy as it was. A little wiggling and rocking and she popped right off. So, once I get the steering loose, will the outdrive mount move freely from side to side, or is that a part of the hydraulics in relation to the rams? I noticed that it looks like it's secured to the hull from the inside. Is that correct? Thanks for all the help Bruce, Bond-o and everyone else that helped along the way. I'll keep ya updated on the progress, and of course, return with any "head scratchers" as they appear. Once I get the manual, things will go a lot smoother. Thanks again!

 

[Bondo]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

So, once I get the steering loose, will the outdrive mount move freely from side to side, or is that a part of the hydraulics in relation to the rams? I noticed that it looks like it's secured to the hull from the inside. Is that correct?

Ayuh,... Ya lost me with that one....

The trim rams have nothin' to do with the steering...

The transom assembly is sandwiched 'round yer hull, held by 6 or 8 bolts/ nuts/ studs....

The steering is disconnect the cable, 'n pull it back,...
then disconnect whatever else is in yer way of separatin' the inner transom plate, from the outer transom assembly...
Ya may, or may not need to pull the P/S actuator,... Never done 1 like yer's....

 

[genuinegemini]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

Ayuh,... Ya lost me with that one....

The trim rams have nothin' to do with the steering...

The transom assembly is sandwiched 'round yer hull, held by 6 or 8 bolts/ nuts/ studs....

The steering is disconnect the cable, 'n pull it back,...
then disconnect whatever else is in yer way of separatin' the inner transom plate, from the outer transom assembly...
Ya may, or may not need to pull the P/S actuator,... Never done 1 like yer's....

Hey, Bond-o. Sorry about the confusion. I was refering to the part that moves the outdrive left and right, but I see how it works now. I got most of the stuff disconnected, but I don't have the right size line wrench for the steering lines. Guess it's a trip to Lowe's! I need to get the wood to make the engine hoist anyway. Thanks for the guidence, Bond-o. As soon as I get the motor out, I will post an update. Thanks again.

 

[genuinegemini]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

Hey Guys, I have another question about the Merc 4.3 and the OMC 4.3; Since they are the same engine, would a Merc exhaust system be able to replace the OMC exhaust, manifolds and whatnot? Just curious. My starboard manifold is cracked pretty good around the outflow opening. I don't even think it can be welded. OMC named replacement manifolds are ridiculously priced. Anyway, it just kinda had me wondering since a Chevy 4.3L is a Chevy 4.3L. Comments and advice welcome!!!

 

[Bondo]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

Since they are the same engine, would a Merc exhaust system be able to replace the OMC exhaust, manifolds and whatnot?

Ayuh,.... I believe you'll find the outlet diameters are Different... by 1/2"....

 

[genuinegemini]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

Ayuh,.... I believe you'll find the outlet diameters are Different... by 1/2"....

Thanks, Bond-o. What exactly do you mean when you say "outlet diameters"? Are you referring to the outlets on the block? I don't get how manifolds from the same year engine of a Merc would not fit. If a 1989 Chevy 4.3L 262 is the same regardless of who's name is on it, why wouldn't the manifolds work? You must be talking about the riser outlet?? All I know, is there has got to be a better way than paying the ridiculous prices people want for an OMC equivalent manifold. I also don't get why the V8 parts are cheaper than the V6 parts. What's up with that!? I have scoured the internet looking for a "fair" price on replacement manifolds, but people are retarded with these things. $500 for a used original on ebay....lmao. Fresh water or not, asking $500 for a 22 year old manifold is grounds for collecting a monthly check. Anyway....

On another note, I tore the engine apart to find out why it was hanging up and not wanting to spin freely, like it did at first. Turns out it was some corrosion in one of the cylinders. It looks like it may have had some water leakage coming in from the exhaust. I took a shop vac to the cylinders and then cleaned them up with a scraper fashioned from a piece of 1/2" polymer and some WD-40. Spins like a champ now with no hang ups. At least that's a piece of good news. Now if I could just find a reasonably priced set of manifolds, I'd be in there.

 

[genuinegemini]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

Hey fellas, in my search for manifolds, I came across this one, http://www.iboats.com/Exhaust-Manifold-Sierra/dm/view_id.222204?cm_mmc=Google+Shopping-_-Engine%20Parts-_-Sierra-_-NA. Could someone please elaborate on why this manifold will not work with my engine? I mean, I get that some minor modifications might need to be made, but I just can't see why it would be impossible or impractical or even complicated, to use this manifold or any other from the same 1989 era Chevy 4.3L 262 marine application. The same principle still applies in the operation of the manifold, doesn't it? Seperate exhaust gases from exhaust water until it's beyond the riser, or am I missing something? Please give me some clarity before I go crazy. This particular manifold is all over the Web for 2 and 3 hundred dollars, but I found it for $129 and the risers for 109. That's a huge difference in prices and much more managable from the wallets perspective. As far as connecting to the "Y" pipe after the risers, I don't see that as being a problem. At least not a major one, such as the manifold mystery. Some detailed clarification would go a long way if anyone cares to share. Thanks for any and all input, guys.

 

[Bondo]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

As far as connecting to the "Y" pipe after the risers, I don't see that as being a problem. At least not a major one, such as the manifold mystery.

Ayuh,.... The motor to manifold interface is the Same,.... ALL else is Different....

The accessory holes will be in different spots, or not there at all...
The outlets are Different diameters... 'n the angles may, or may not be the same...

 

[bruceb58]

Re: 1990 OMC 4.3L Equivalent and Swap Complexity???

Your problem is adapting from the outlet of these new risers to the inlet of the Y-pipe if the diameters are different. That is what Bondo is saying.