Please Help! Mercruiser closed inline cooling system removal

I have an anti-freeze leak and I am having a hard time removing the thermostat housing to replace the gasket. Am I suppose to remove the drive belt before I take the housing out? If so, what is the best way to take the belt off? My book is hard to follow. I was trying to take the housing off by either not taking the drive belt off at all or by just loosening it. I am not familiar with doing the timing, when I have to replace it. Please help!
Also, once I get the housing off, where is the best place to get the new gasket?
Thank You!

Re: Please Help! Mercruiser closed inline cooling system removal

You're going to have to do better than that, there is a lot of difference in a 70's closed cooling system and those of the 2000's

Re: Please Help! Mercruiser closed inline cooling system removal

ok 1987 inline...alpha 1 ss

Re: Please Help! Mercruiser closed inline cooling system removal

mcook5 said:

ok 1987 inline...alpha 1 ss

Click to expand...

Would that be the inline 3.7 or the 3.0? And you have a ss (race) drive on an inline??????

Really, Really need to know what you actually have to answer your questions.

Re: Please Help! Mercruiser closed inline cooling system removal

What motor? 120 165 185?????? Any info will help.Jerry

Re: Please Help! Mercruiser closed inline cooling system removal

Loosen Alt. and belt will be free, remove waterpump pulley and you can get the therm. housing bolts out.

Re: Please Help! Mercruiser closed inline cooling system removal

I'm sorry...it is the 170 HP. I was told it was an SS, but I might have misheard. I have only had the boat for a month. This is as much as I know...I wish I knew more :/ that is what is so frustrating. 1987 Mercruiser I/O 170 hp Alpha 1. I was told it has a closed cooling system. The gasket looks totally shot and I now obviously need to replace it, but I am having a hard time getting the whole housing unit off. Like I said, I am very inept when it comes to mechaincal work, so I don't think I'd be able to time the belt when I tighten it back up, if I have to. Is there an easier way? What would yuo suggest.
I appreciate everyone's input so far. I wish I could give you more info. My SOLEC manual is very hard to follow, so I need someone else's opinion or guidance. Thanks!

Re: Please Help! Mercruiser closed inline cooling system removal

Here are link to the OEM service manuals for your engine and drove

Engine manual about 360 MB

Drive manual scroll to the outline, click on section letter you want to download.

Re: Please Help! Mercruiser closed inline cooling system removal

Thanks..i will check these out. Hopefully this one is more user friendly.