7.5 merc lacking power

[nickb911]

After much effort, it's running reliably (for now). However, seems to be lacking top end. Could a slight air leak cause this? One of the gaskets on the fuel pump is old and brittle. Also, prop is old and looks pretty dinged up. I'm thinking of replacing. Will it really make a difference and if so what prop should I use?
It's a 1981 Merc 7.5 pushing a 14' vhull aluminum.

 

[tashasdaddy]

Re: 7.5 merc lacking power

air leak would definately effect it. have you checked spark and compression?

 

[nickb911]

Re: 7.5 merc lacking power

I have not checked spark and compression. I do know it ran fine last fall. I did run it with one plug/wire removed and then the other removed to determine if they were both firing. How do I check spark and compression properly.
Thanks