1977 OMC Sterndrive not Lining up after drop in!!

[davidbrookstone]

1979, Ford V8 260, OMC 800

This is a replacement motor, original was a 235. Dropped the engine in with everything but the upper/lower unit. The fore engine mounting bolts are lining up perfect and are in. The rear bolts are off by about 2 inches too far aft and port. See the picture below.

Tried using a come-along to get the engine aft to come port side some but it does nothing so I stopped (thought it floats on those front mounts and could give a little.)

Are the two engines/intermediates/rear mounts different sizes or am i just not lined up? Do I need to make new holes? I did notice that the trim is all the way down in the front could that be it? If so, could i just hook a battery up to the trim pump instead of connecting the wires?

 

[Boomyal]

Re: 1977 OMC Sterndrive not Lining up after drop in!!

I can say for certain that the '77 electric had a different intermediate housing than the '79 hydro-mechanical intermediate housing. It would not be a stretch to think they might of had different mounting points as well. It is not surprising that the front engine mounts line up as a SBF is an SBF. The other issue that potentially concerns me is that the boots might be different as well. Somewhere along the line OMC changed the boot and therefore the shape of the hole in the transom. I do not know exactly what year/model they did that and I also do not know if the boot mounting profile on the IH housing differed with the different dimension boots.

Maybe you will need to do as I did and re-use your electric shift IH with your new motor and outdrive.

 

[davidbrookstone]

Re: 1977 OMC Sterndrive not Lining up after drop in!!

Maybe you will need to do as I did and re-use your electric shift IH with your new motor and outdrive.

The bell housing is what the mounting bolts are and that's whats not lining up (the two aft mounting legs.) I wonder if ill need that switched out too.

 

[Boomyal]

Re: 1977 OMC Sterndrive not Lining up after drop in!!

I didn't distinguish between the 'bell housing' and the total intermediate housing assembly, ie, every thing between the engine and the outdrive. I could not speculate about mixing ' intermediate housing' components.

 

[davidbrookstone]

Re: 1977 OMC Sterndrive not Lining up after drop in!!

I didn't distinguish between the 'bell housing' and the total intermediate housing assembly, ie, every thing between the engine and the outdrive. I could not speculate about mixing ' intermediate housing' components.

Got ya, sorry, I'm still learning the names of everything. Whats a shame is I threw away my old bell housing. All I have is the portion the steering cable connects to.

Do you think I would be fine just lining up the engine straight and drilling new mounting holes then throwing my upper and lower on it?

 

[Boomyal]

Re: 1977 OMC Sterndrive not Lining up after drop in!!

......Do you think I would be fine just lining up the engine straight and drilling new mounting holes then throwing my upper and lower on it?

That is pretty much what you would have to do. Two things first, however. I would position the motor/ IH assembly then make sure that your original boot fits over the new intermediate housing. Then I would make sure that the boot perimeter holes line up with your transom holes. At that point you could still shift your motor/IH assy around til they all fit. Then drill your new holes. Maybe the front ones still work and maybe they won't. Just make sure everything is square.

As I said before, I do not know for sure when they changed the boot shape and, in any case, I do not know if they changed the hole shape, where the boot clamps to the IH. I think they did it in '79, when they went to the Hydro-Mech drive like you got. In any case, the new style boot will not match the hole in your transom.

I would also fill the old stringer holes with epoxy. I would also dribble some epoxy down the new lag bolt holes so that water will not get down there and rot the wood around the bolts. You can do that on your existing front mount holes if you re-use them. Use enough epoxy that the bolt will force some of the epoxy up out of the holes as you snug the bolts. You can then wipe off the overflow.

I think that you will also have to get a new exhaust boot for one side. On the electric shift IH, I think it is the right side had a reducing bell between the elbow and the intermediate housing port. Your new one has the same size exhaust port on both sides. A plus is that the '79 IH has a fluid drain plug where the Electric shift IH did not.

I also hope you have all the shift cables and converter box for the new drive?

 

[davidbrookstone]

Re: 1977 OMC Sterndrive not Lining up after drop in!!

I also hope you have all the shift cables and converter box for the new drive?

I overestimated how much I was educated about this drive system. I had no clue that the upper was either mechanical or electric shift. I do not have the mechanical shift cables, but do have the converter box on there still.

Since I have an electric shift out-drive (from the 1977 235hp,) shouldn't I just be able to slip the shift cable through the new 260 IH and everything will work? The only thing I'm seeing I'll have a problem with is that the wiring harness from the old engine is not matching the new ones. Any idea on what to do about that?

P.S. I got the boot on, its was a stretch going from a circumference of 39" to 45" but everything will line up fine. Looks like the front mounting holes will be fine, and the rear ones will need to be re-drilled. I am also going to reinforce each mounting leg with welded steel elbows drilled into the stringers.

If I am still misguided, please let me know, I'm learning a lot as of lately.

Thanks for your help!!!

 

[Boomyal]

Re: 1977 OMC Sterndrive not Lining up after drop in!!

I am a little confused. Did you not go from a '77 boat and electric shift outdrive/IH to a '79 outdrive and IH? If so, which stern boot are you trying to use. The one that came with the boat or one that came with the new outdrive? I'll address your other questions once I am clear on the above.

 

[davidbrookstone]

Re: 1977 OMC Sterndrive not Lining up after drop in!!

I am a little confused. Did you not go from a '77 boat and electric shift outdrive/IH to a '79 outdrive and IH? If so, which stern boot are you trying to use. The one that came with the boat or one that came with the new outdrive? I'll address your other questions once I am clear on the above.

Had a '77 boat, engine (235), electric shift outdrive/IH. Engine was seized, bought a used '79 motor (260) with IH, NO out-drive.

The '79 requires the bigger boot (circumference of about 45" versus 39" on the '77.) Got the fresh '77 smaller boot on the '79 IH it looks like it will work.

 

[Boomyal]

Re: 1977 OMC Sterndrive not Lining up after drop in!!

Got it. Not sure what if any difference in the diameter of the shift wire/shift cable holes were between the the electric shift IH and the Hydro-Mechanical IH. I went the otherway around but I did not do the conversion so I do not know if they had to enlarge the passageway in my electric shift IH, to accommodate the fatter shift cable. It should be easy enough to determine. If the grommet on your electric shift cable is snug in the passageway, you should be good to go. Your new IH should also have a forked clip, with a bolt, to hold the grommet in. You could always use some RTV sealant if you need to.

Hang on to that shift converter as you could use it if you ever upgrade to a hydro-Mechanical. However, If I was going to upgrade today, I would go to the full Mechanical. Your white shift converter would not work for that.

Not sure what the deal is with the wiring harness. Whenever I remove one from an engine I always mark what each lead goes to. That would have made it easy to see where, on the new engine, your original wires needed to be plugged in. The only difference I can see, off hand, is that your new tilt motor is a 3 wire instead of a two wire.

 

[davidbrookstone]

Re: 1977 OMC Sterndrive not Lining up after drop in!!

Got it. Not sure what if any difference in the diameter of the shift wire/shift cable holes were between the the electric shift IH and the Hydro-Mechanical IH. I went the otherway around but I did not do the conversion so I do not know if they had to enlarge the passageway in my electric shift IH, to accommodate the fatter shift cable. It should be easy enough to determine. If the grommet on your electric shift cable is snug in the passageway, you should be good to go. Your new IH should also have a forked clip, with a bolt, to hold the grommet in. You could always use some RTV sealant if you need to.

Hang on to that shift converter as you could use it if you ever upgrade to a hydro-Mechanical. However, If I was going to upgrade today, I would go to the full Mechanical. Your white shift converter would not work for that.

Thanks so much for your help, I really appreciate it and hopefully this thread will help any other adventurous people that dive into an older omc system!

Do you know what I should do about the wire harness ends not matching up? There is two circle ends on the 77 and one black circle end and a flat one on the 79... am I gonna have to do some splicing?

Thanks again Boomyal!!

 

[Boomyal]

Re: 1977 OMC Sterndrive not Lining up after drop in!!

Not sure what the deal is with the wiring harness, especially without seeing what you are working with. Whenever I remove one from an engine I always mark what each lead goes to. That would have made it easy to see where, on the new engine, your original wires needed to be plugged in. The only difference I can see, off hand, is that your new tilt motor is a 3 wire instead of a two wire, plus the new motor wiring will not have provisions for your electric shift.

You should have two big fusible connectors mounted on the engine. Mates on the boat harness were meant to plug into those. Can't you use the motor harness off the original motor?

 

[davidbrookstone]

OK, reviving an old thread here. Just got back to working on my boat...lol.

I still am a little confused on the best route for me to go. The cheapest would be move the engine fore-ward, square it up, then saw the transom hole bigger, buy the bigger transom seal, and plop on my '77 235 outdrive...

the route I think I am going to go is:

buy an omc 235 bell housing 0981350 with legs, swap the '77 235 electric shift intermediate onto that, and then the rest is history, right? Am I going to run into any issues with the omc 250 engine mating to the bell housing?

On to my next issue which is figuring out how to wire up the '79 250 engine pigtail to all the '77 235 accessories... that will be fun.

 

[jbcurt00]

Its your topic, you are free to revive it as needed.

Good luck w the drive swap

 

[Boomyal]

If you end up getting back to the original '77 Intermediate and bell housings, you should be good to go with one exception. I believe when they went from the electric shift to the hydro-mechanical shift, they beefed up the splines on the 'drive shaft' that fits into the coupler on the flywheel. The electric shift splines were much finer and more numerous and will not mate with the later coupler and vice versa. The good news is that the later shaft and bearings will work in the older Electric shift IH. Replace any seals when you swap shafts. Also be mindful that you will probably need to enlarge the passageway for the mechanical shift cable.

 

[davidbrookstone]

Ending up using old intermediate from 77 electric shift and the outdrive from it too. I have everything together, water testing today