Engine Gasket Leak-Cooling System at Powerhead

[Yon'der Horizon]

Hey Guys, so i just finished fixing up an electrical issue on my Evinrude 200XP (1990) and took 'er a test drive, when i noticed water filling up in the motor shroud! Yikes! turns out, the lower gasket blew out, the one where the lower unit attaches to the powerhead. not sure what the proper term for it is. the gasket itself is sticking out about a 1/4" at the break with a small 1/8" gap now. this appears to be a seal for the water jackets where only water flows.

This might be a stupid question, but do you think JB Weld would fill the gap strong enough for a temporary fix? i'm guessing there is no more than 30psi of pressure going through this cooling system, but i could be wrong.

Otherwise, how difficult will it be to get to this gasket? looks like either the lower unit would need to come down, or the powerhead up. maybe neither would have to come apart. the section that needs repair looks like a basic pan (like a cover on the very underside of the powerhead) and it may be reachable by removing the engine cover shroud.

Any thoughts would be greatly appreciated. Trying to figure out if this is a repair that I am able to make on my own (i'm pretty mechanically inclined). because i know a professional fix would be upwards of $1000! thanks guys!

 

[Yon'der Horizon]

Re: Engine Gasket Leak-Cooling System at Powerhead

just to clarify, i was looking at the parts list and i believe the leak is occurring on top of the midsection (what is called the ADAPTER, Exh. hsg - to the powerhead) and the gasket sits on top (between the ADAPTER and Powerhead) hope this helps. thanks!

 

[daselbee]

Re: Engine Gasket Leak-Cooling System at Powerhead

This is a huge co-incidence. Gatormike on this forum just went thru the exact same thing. Look at his posts.

All of this must be done with the lower shrouds off.

You have to get to that gasket by lifting the powerhead. If it were me, I would put a lift eye on the flywheel, hook up a cherry picker, and then remove large bolts, three on each side, four fasteners in front (bolts and studs), and three fasteners in back (bolts and one stud). I specify because many guys miss a bolt or two.

Disconnect the shift shaft from the lower port side under the carbs.

Lift the p'head, and be careful that the driveshaft doesn't bind in the crank end as you lift. It can be done.

Clean gasket surfaces, both on block bottom and exhaust adapter, install new gasket, check and re-grease driveshaft splines, lower p'head onto driveshaft splines, again being careful to avoid binding, (IT CAN BE DONE), and re-install fasteners. The six big bolts are torqued to 20 ft-lbs, and the smaller fasteners to 150 in-lbs. Note I said "inch-pounds" for the small ones.

Easy to do.

 

[Yon'der Horizon]

Re: Engine Gasket Leak-Cooling System at Powerhead

thanks daselbee! yea i have the lower shroud off, and removed all the bolts n nuts. now i just need a lift and a lift eye. i may be able to borrow one from my neighbor who is an outboard tech. wish i was strong enough to lift it free without a picker! that 350 lbs is bonded pretty well at the gasket!

this will be my first time pulling a p'head. how far up does the head have to come? and what else will be coming with it? i'm assuming the main driveshaft, as you mentioned. is there anything else i should be aware of, i.e. marking shaft position, re-lubing, etc....

thanks again! hope this works out. once fixed, i have a laundry list of other things that need tweakin' on the motor. never ending... gotta start somewhere! =)

 

[daselbee]

Re: Engine Gasket Leak-Cooling System at Powerhead

Well....nothing else will come up with it. The driveshaft is splined into the end of the crank. It will slip free if you don't let it bind. The whole rig will be heavy toward the rear, with a tendency for the rear to be lower than the front.

Notice on the rear of the block, down at the joint in question, there are two bosses on each side made specifically for prying at those points. You will need to pry it loose I think. DO NOT DAMAGE the mating surface of the block/exhaust adapter joint. Go easy.

Driveshaft has a special grease...a moly grease by OMC. I bet you could find a substitute at a parts store. I think it is a high temp moly grease so it won't melt and run out of the joint. There is a little ketchup packet of it included in a complete OMC water pump kit.

Do not overdo the grease...you can put too much on, especially the driveshaft end, and cause a hydraulic lock where the driveshaft will not go all the way down. Not good. Just be sparse with the grease. In fact you may not need it at all.

You have to get it high enough to clean it properly. I use an air die grinder with a 3inch abrasive wheel on it, sorta like a round scotchbrite pad. Go easy with that also. You don't want to remove aluminum, just gasket.

It will be easy for you, I think.

 

[GatorMike]

Re: Engine Gasket Leak-Cooling System at Powerhead

I just came across this thread and wanted to add something. It would be a good idea to make sure you get a good gasket. If you read my thread on the subject you will see endsapmgr made the coment that on some models OMC used a paper gasket and they have later came out with a better gasket made of aluminum sandwiched between paper. For sure use the better gasket. The reason mine blew in the first place is because I purchased a cheap gasket kit online when I rebuilt my powerhead and the gasket was of the paper type. Later when I had to go back and repull my powerhead I purchased one of the good gaskets. It is a lot stiffer and I don't think it will blow out.

 

[Yon'der Horizon]

Re: Engine Gasket Leak-Cooling System at Powerhead

Yep, did the replacement last night. Went pretty smooth. We got the 'better' gasket. It's a rubber/paper with aluminum sandwiched in between. Wasn't sure if i needed to use a sealer, since i got mixed opinions. But i needed something to adhere the gasket to the upper P'head so i used a non hardening gasket adhesive/maker applied lightly all around the gasket. Not much, but just enough to tack it evenly. I would think it would help ensure a tight, clean bond.

The only thing that went wrong was, the gasket fell down just a tad while realigning the spline, so i had two hands in there when my buddy turned the flywheel and BAM! the P'head dropped two inches right on my hands. Wow does that hurt! Like getting your hands slammed in a car door! Lesson learned. All in all for this being the first time doing this, it was very easy. For anyone looking to do it as well, don't be 'a scerd easy job. Thanks for all the pointers guys! Back to the water tomorrow!

 

[ezeke]

Re: Engine Gasket Leak-Cooling System at Powerhead

Just for future reference, you should never try to remove or replace the engine with the drive in place; that's a great way to ruin your crankshaft.

 

[daselbee]

Re: Engine Gasket Leak-Cooling System at Powerhead

Lift the p'head, and be careful that the driveshaft doesn't bind in the crank end as you lift. It can be done.

Clean gasket surfaces, both on block bottom and exhaust adapter, install new gasket, check and re-grease driveshaft splines, lower p'head onto driveshaft splines, again being careful to avoid binding, (IT CAN BE DONE), and re-install fasteners. The six big bolts are torqued to 20 ft-lbs, and the smaller fasteners to 150 in-lbs. Note I said "inch-pounds" for the small ones.

Easy to do.

I knew someone would disagree....this is the way I have always done it. If you are careful, and don't bind the crank, it can be done, and saves the labor of R&Ring the lower.

OP, how did it go back on? Easy or difficult? Did it bind coming off?
Give us some details on the removal and re-install process.