gell seal II for lower exhaust housing to ph adapter?

[horiconducker]

Is it really necessary to use the gel seal or locate 518 for sealing the lower exhaust housing to the powerhead adapter on my 1988 70hp? OEM manual calls for it. Would a little cheaper aerobic sealant work? Now that i have it apart it does not seem to be a critical joint as far as sealing goes, like the crankcase would be. I can see that joint being critical for alignment of the lower unit and powerhead though. The inner exhaust housing has its own gasket to the powerhead adapter and the adapter has a gasket to the powerhead. I will order the right stuff if it is really needed. thanks ducker

 

[James R]

They must have a reason for using their sealant. I have always used the omc gasket and thread sealer on both sides of the gasket and never had a problem. A small can costs around $10. It tends to settle to the bottom of the can so mix it up good. It comes with a brush in the cap for ease of application.