Transom leak 1991 OMC Cobra

Previous owner had hit rocks. scraped bottom/rear/center of hull & damaged lower unit.
Lower unit & prop were replaced and hull damage repaired (never cracked/went thru the fiberglass). Boat runs fine, but has water leaking into bilge. Looking at outdrive from rear of boat, water is entering only at lower, right corner where outdrive mounts to transom. can actually see a slight gap there, where-as the gimble housing seems to be tight against the transom in other areas. Tap-Test on transom seems to show no rot-solid. have seen some posts where "hit something" enough to dislodge the housing enough it starts leaking- retightened mounting nuts fixed it for 1 guy, replacing the transom seal worked for another guy. I tried tightening the mounting nuts, did close the gap slightly but not enough (dont want to overtighten).
So, short of removing everything, isn't there a shortcut method to only replace the transom seal and see if it fixes the problem? Looks like the seal for this model is a rope-like seal.
Yeah, Im not looking forward to doing it the "right way", at least not yet.
Any suggestions ARE appreciated.

Re: Transom leak 1991 OMC Cobra

Howdy,

Welcome to iboats....

Yeah, Im not looking forward to doing it the "right way", at least not yet.

Click to expand...

If what you say is true, there's only one "right way".

Pull the drive, pull the engine, pull the transom mount.

You may have something broken in there that you won't see until the cut-out is inspected directly.


Also, if it had an impact that caused the problem, the alignment may be far enough out that it will cause a coupler failure so you'd be pulling the drive and engine anyway.....

If you don't have one, now would be a good time to obtain an OEM OMC service manual....


Regards,


Rick

Re: Transom leak 1991 OMC Cobra

I am getting my four winns done right now for the same problem. Mine is leaking at the steering pin shaft.

I agree you could have somthing very serious going on. Place a bead of calk around the outside and see what happens. If still leaks, yank the engine and fix it the right way. I will have $1700 into mine when done.

Re: Transom leak 1991 OMC Cobra

A good bead of 5200 will solve your problem. If it still leaks , do some bellows checking.

Re: Transom leak 1991 OMC Cobra

I would check the bottom bolts on the transom plate...mine was loose causing water to come in the bottom of the unit. you can check them without pulling the motor. Start simple and move on from there.

Re: Transom leak 1991 OMC Cobra

catfish hunter said:

I would check the bottom bolts on the transom plate...mine was loose causing water to come in the bottom of the unit. you can check them without pulling the motor. Start simple and move on from there.

Click to expand...

Can you please let me know how to check these without pulling the motor?? we also have 1991 cobra and having the exact same problem...leaking around transom. thought maybe the bottom bolts were loose and planned to pull the motor today to check them...if there's a way around this would love to know how. i cant seem to get to the bottom ones or see them around the engine. i filled the back with water to find where the water was running out and its around the transom...though it may just be a seal but when we shook the drive a bit the leak didnt seem to get any worse, we assumed if a seal it would get worse since shakingw ould cause the seal to break free...i was able to find 2 of the bolts without removing the engine and they seemed loose so planned to pull motor to check the rest. open to any other suggestions....thanks