i used to have a boat with an 81 40 hp merc. NOT the 402 model. I sold the boat and motor seperatly. I sold the motor to a buddy of mine. Well this past weekend he took the motor out on his 16 ft aluminum boat (sylvan, i believe, but dont quote me on that). So he said he got maybe 30 minutes into running it, and he noticed that there was ALOT of water pouring out of the front of the cowling. and it was getting everything wet and causing the motor to cut out. So i told him to bring it over and i'd have a look at it since i did all the repairs when i owned the motor and i knew it fairly well. <br /><br />Well this is what i found. When i took the wrap around cowling off, i was greeted by a 4 foot stream of water shooting out of the back of the motor. Almost looked like it was pouring out of the cylinder itself 
<br /><br />But it wasnt. i pulled the water jacket cover off. And i found that there is 2 "tower like" looking things.. instead of seeing the two pistons. really hard to describe, but im sure some of you know what im talking about. anyways, it turns out that one of these was half rotted away (salt water here) and it wasnt matching up with the water jacket cover, thus, letting water escape. <br /><br />so what i did, was basically reformed the whole thing with jb weld. so that it would sit against the water jacket cover properly. <br /><br />He had the boat out yesderday and said he found nothing leaking. Even at WOT. <br /><br />so my question is, does anyone here know what im talking about? was this a common problem when running these motors in salt water ? im trying my damndest to describe the problem accuratly, but its really hard, and i dont have a digital camera
<br /><br />But it wasnt. i pulled the water jacket cover off. And i found that there is 2 "tower like" looking things.. instead of seeing the two pistons. really hard to describe, but im sure some of you know what im talking about. anyways, it turns out that one of these was half rotted away (salt water here) and it wasnt matching up with the water jacket cover, thus, letting water escape. <br /><br />so what i did, was basically reformed the whole thing with jb weld. so that it would sit against the water jacket cover properly. <br /><br />He had the boat out yesderday and said he found nothing leaking. Even at WOT. <br /><br />so my question is, does anyone here know what im talking about? was this a common problem when running these motors in salt water ? im trying my damndest to describe the problem accuratly, but its really hard, and i dont have a digital camera 