89 3.7 mericruise coolant problems

CrAzYsEaN

Recruit
Joined
Jun 29, 2010
Messages
5
Hi there, I am TOTALLY new to the boating scene and this site...ive been reading threw the threads and the input people give back is amazing. So I have a few basic questions and issues with my boat I guess.

First off I was curious because there is two collant tanks on my engine one on the lower left side of motor and one on the top right side....what do each one cool?? are they both for the engine or what? also the top tank keeping loosing coolant but I cant find a leak anywhere, and the side of the tank seems to be smoking once the engine gets hot, but dont know why??? My boat has an issue with overheating obviosly, only at a slow idle though..if im wide open it stays below 180ish...but slower speeds it shoots up so i shut her down, whats the simple things to check for that?

Second, like i said im a newbie...on the outdrive at the bottom coming from the boat side to the prop side there are some hoses running....there is one that is big prob like 4inch or so, mine is all torn up like not even connected to eachother anymore....what does that hose for? doesnt look like there is anything in it, fluid or what not so not sure...i was going to take a pic but forgot so if that helps i can

Thanks, Sean
 

YeboGogo

Seaman
Joined
Apr 25, 2010
Messages
56
Re: 89 3.7 mericruise coolant problems

Metal one is part of the system that basically separates out air.
The plastic one is the overflow. It pushes and pulls water as it expands or contracts since its under pressure.

Keep the metal one near full and the plastic one between its marks.

Check to see if the heat exchanger (big cylinder) is 4" or 3". You might want to take it apart and clean it with muriatic acid. Also check for pieces of impeller.. AND make sure you have a good impeller...


If the lowest tube is broken between transom and outdrive its the exhaust bellows. Sometimes critical if below the waterline otherwise just noisy. A bit of a pain to change.


How i love these things.
 

stonyloam

Vice Admiral
Joined
Mar 13, 2009
Messages
5,827
Re: 89 3.7 mericruise coolant problems

OK, first thing to do is go to "adults only", #9, download service manual #8 (470/3.7 engine) and manual #6 (alpha I outdrive). Look them over. Second: You need to use the proper boating terminology, for where things are. The transom end is aft, and the bow end is forward. If you are standing behind the boat looking forward your right is starboard and your left is port, they never change no matter which way you are facing. For example your helm ( steering wheel) is on the starboard side even if the way you are facing has it to your left. The torn up tube is probably your exhaust bellows, suggestion that all of your bellows are in bad shape and will probably have to be changed. Your coolant loss could be a problem. Sounds like you need to do a compression check and a cooling system pressure check (not too hard to do). You can borrow the tools to do both from autozone (free loan). Take a few pix and get back with any questions. Lots of help here. Welcome to the 470 club.:D
 
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