I'm a new member here so please bear with me .

I have a 1997 4cyl 40hp Magnum Mariner. Right now it sit's bone stock and runs pretty good. I am now not happy with the amount of hp it has, so right now I am looking to squeeze more perfromance out of it. What exactly could be doen to get more power but keep longevity of this engine?

Since I have to pull the power head off to put new upper motor mounts in, I was thinking that this could be the best time to do some motor mods. I was thinking of throwing in a set of Boysen CF reeds and do some porting as well. Also thinking I could maybe bore all the cylinder holes out .040 and run a set of Wiseco pistons in it. Also though about putting some velocity stacks on it. If there is anything I can do to the tuner as well let me know.

Thanks for your help guys!