OMC Cobra gearcase - drain plug / pressure port - ooopps!

[JaymeRay]

I know this topic has been talked about in the past, but I couldn't find the specific answer that I was hunting in the previous posts. I am one of those guys that took out the screw in the gearcase and the binding nut fell down inside. I realize that it is somewhat of a mystery what the port is/was used for and wish I would have never removed it... but too late for that.

My question... I like the idea of putting the rubber plug in that another post referenced; however, I am concerned about the binding nut that fell inside. Can that nut cause any damage on the inside or can it wait until the next time I do routine maintenance to pull the outdrive? Just don't want to do any unnecessary work if the nut is not going to cause any problems. Thanks much! Jayme

 

[Idlespeedonly]

If it were mine I would pull the drive to get the nut and fix it properly. It will cost less than 10 dollars to do it the right way.

 

[HT32BSX115]

I am one of those guys that took out the screw in the gearcase and the binding nut fell down inside. I realize that it is somewhat of a mystery what the port is/was used for and wish I would have never removed it... but too late for that.

My question... I like the idea of putting the rubber plug in that another post referenced; however, I am concerned about the binding nut that fell inside. Can that nut cause any damage on the inside or can it wait until the next time I do routine maintenance to pull the outdrive? Just don't want to do any unnecessary work if the nut is not going to cause any problems. Thanks much! Jayme

Howdy,

Welcome aboard!

Well you are a member of a rather large "club"!!

No one seems to be able to say exactly what that hole is for.......... but because it's pressurized by the raw water pump, leaving it open will cause a reduction in water flow to the engine because it will flow out that hole!

A rubber plug might work but if the pressure is sufficient, it will blow that plug out and your only indication will be the "pegged " temp gage!

Also, if that nut-plate gets rattled around in the "right" way, it could get picked up by water flow/turbulence in the chamber and placed against or go into the plastic water fitting in the gimbal mount.

That could also either block/restrict water flow to the engine causing an overheat.

I would pull the drive and retrieve the nut plate.

Regards,


Rick

 

[JaymeRay]

Rick... Thank you very much for the explanation. Looks like I'll be getting my feet wet pulling the drive.

Have a great day!
Jayme

 

[jerryjerry05]

When they started selling them at the dealer where I worked.
We were told that it was a casting plug or hole.
Kinda like a freeze plug hole.
Yup get the piece out and put it in right.
If it's on the left side it's part of the water passage and might get up in the pump.
On the right it's part of the shift mechanism space.(if my memory's right)