'92 OMC 4.3L Cobra

[pshawn20]

Hey gang, I'm looking at upgrading to a slightly bigger boat than the 16' Invader bowrider we have with the 2.5L Merc (Alpha One Gen 1).

I'm interested in a '92 Four Winns Freedom 180 with a 4.3L OMC Cobra engine/outdrive. The hesitations I have are;

1. It's an OMC...which has a bad rep around most boat forums...however, this outdrive is the one with the red shifter cables, so apparently those are much better than the old gear chewing ones! I know parts can be hard to find, and many marine mechanics don't want to work on them. The engine seems to run well (new bellows in '16).

2. The other issue is that he's changed the battery and gone through 2 different alternators due to an overcharging issue. Something is telling the alternator that the battery needs more juice...and the alternator gets super hot and charges at 15-16 volts. Could be a bad ground...bad send wire...bad regulator...bad harness.....

He's taken very good care of the boat (it's worth 8k easy, but he'd take 5k because he's frustrated he can't fix it...and he bought a camper trailer, and his wife said "one or the other!". Vinyl looks like it's 10 years old with little wear.

My question is...should I be concerned about it being an OMC...and should I be concerned about the overcharging issue being more than a 1k job? If I pay 5k for the boat, I could put another 2k into it and still be ahead value-wise.

Thoughts?

 

[Lou C]

Overcharging issue is a cheap fix. Disconnect the sense wire from the alt and tape it up in the harness. Then make up a 16 gauge wire that connects to the sense terminal and the large B+ terminal on the alt. This should bring it down to 14.2v. The problem is caused by high resistance in the sense circuit. I learned this from Arco Marine when I bought one of their alternators to replace the original. The instructions on the box said to wire it this way if the charging volts is too high. I did this about 6 years back and it’s been fine. Try it and report back. My OMC has been great.

 

[Lou C]

PS when you water test the boat make sure it shifts easily into gear and out of gear and does not jump out of gear under power. When the drive is in good shape and adjusted properly it will shift very easily

 

[pshawn20]

PS when you water test the boat make sure it shifts easily into gear and out of gear and does not jump out of gear under power. When the drive is in good shape and adjusted properly it will shift very easily

Thanks Lou...haven't tested it yet, as the buyer is now re-thinking if he wants to sell it. He thinks he can get more in the spring if he can figure out what's wrong with the battery/alternator. If I end up going ahead with it, I'll be sure to post updates.

 

[louc]

Before you go ahead with it, see if any shops near you will work on them. So for example if you need to have the drive re-sealed, and don't have the special tools needed, then what? The lower unit is very similar to the common V6 Evinrude/Johnson outboard gear cases, the upper unit not anything complex but there are always special tools needed for certain jobs.
The solution to the owners problem is actually really simple but he might not know that yet! I would not have found out myself, if I didn't buy an ARCO alternator and find those instructions in the box!