Logo
FULL SITE MENU

1988 2.3l flapper melted

F

Ftitzl65

New member
Engine overheated and now i need to replace the flapper. I have that ordered
I am planning on removing the outdrive to check for debris. I used a 1/2" tubing on my shop vac and recovered a melted piece of the old flapper, and some smaller
I am not confident that I got all of it, so off comes the drive and I may have to split it.
What gasket would I need for the OMC Cobra drive upper and lower halves?
What advice would you offer for this task?
 
No gasket but there is are o-rings IIRC
Look inside the upper gear unit when you have it off, melted flapper bits often will be right past the shift selector rod
When I had an overheat some years back I found them in the bottom of the exhaust passage in the transom mount, used one of those 3 jaw puller tools to get it out.


O-rings part # 57
water tube grommets can also be melted/distorted if you had an overheat part # 79
water tube guide might be scorched but still useable part # 78
when I had the overheat one of the water tube grommets was distorted, and water tube guide was slightly scorched, replaced all of it.

Note, if used in salt water or water with high mineral content the upper drive can get stuck on one of those o-rings, it can be tough to get off. I had to think of a way to use a couple of scissors jacks to get mine apart (salt water use). Be careful with prybars, etc., my way of doing it is safer for you and won't break the drive housing either.
What I did was use a couple of bolts and nuts that fit in the lower front mounting holes, and a long piece of all thread for the trim ram rod. I had the drive on a drive jack. I had 3 scissors jacks, one under each side of the all thread, and one under the 2 bolts in the front mount holes, applied even pressure and it came right off.

Cobra with bolts and all thread to remove upper.jpg
 
Droid said:
No gasket & I wouldn't go that far.
If you're concerned, just pull the prop & look in that end.
Click to expand...
But it it was overheated and ran for a long time, it's possible that some of the oil seals have been damaged, as Louc posted- my Mercruiser needed all of the seals in the upper and the ones that were in the exhaust path had very little rubber left. Also, the water pocket and raw water pump covers were melted. I found the impeller parts and half of the flapper in the raw water intake area, next to the slots.

I used an endoscope camera to look into the exhaust, just because I had it- they're not expensive now and can be as small as 1/4" diameter.
 
Just remembered this....on the Cobra bellcrank, there is a little o ring right near the exhaust passage in the pivot housing, this can also get fried in an overheat, and that will allow water to leak into the cavity where the bellcrank lives. I was getting water in there the season before last and replaced it, now no more water.
https://www.marineengine.com/parts/...acturer=OMC+stern+drive&section=Transom+Mount part number 2 is what I'm referring to
On mine one of the water tube grommets was definitely deformed. Imagine that hot exhaust going through there with no cooling water.
 
Thanks all.
Vacuum from the top, and then pulled the prop and ran water through it for about 15 minutes and some small bits were washed out along with the chunk that came out the first attempt. Replaced the impeller with a new one from Offshore marine. Used high temp.red axle grease on the contact points. Will have to wait for the truck to get out of the shop to bring the boat to the lake for an actual test run I am reluctant to put muff on now


t
 
Back
Top