Replacing Exhaust Gaskets on 1978 70hp

[outfishing13]

I have a 1978 70 hp Evinrude (model #70873c). In diagnosing some acceration and idling problems, I noticed some moister in the #3 cylinder when I removed the spark plug. I figure it is a faulty head gasket or exhaust manifold gasget. I have order a head gasket and head cover gasket as well as the three gaskets for the exhaust manifold and cover. I just wanted to know if anyone has replaced the exhaust manifold gasket without removing the powerhead? It seems a little tight on the bottom bolts down inside the housing. I am just a little reluctant to take off the powerhead if I can replace the exhaust manifold gaskets without taking the powerhead all the way off.

This is my first outboard and I have really enjoyed it this spring and summer until it developed this problem. It's mounted on a 16.5 foot Aluminum Starcraft. This forum and manual I have (Clymer) have been really helpful in diagnosing the problem. Just not a lot of info on replacing parts.

Thanks for an help and suggestions.

outfishing13

 

[tashasdaddy]

Re: Replacing Exhaust Gaskets on 1978 70hp

Clymer get the real thing OEM.

 

[outfishing13]

Re: Replacing Exhaust Gaskets on 1978 70hp

Well, I started into the exhaust manifold today and figured out how to take it off without taking the powrhead off. All I had to do was unbolt the lower cowling and drop it down a little bit and that gave me room to get the manifold bolts loose.

The middle exhast gasket was the culprit and was broken in two places. I took some pictures that I will try an post.