1987 Merc 170 general questions

[JNormV163]

I can Imagine there are a lot of questions regarding this engine. So I'm sorry if i sound like a broken record. I'm definitely not new to mercruisers but I am new to this particular design and set up. I bought a 1987 19' Sea Ray Seville with a 470 170 Merc in it for $500. (long story) motor was winterized but before I start it for the first time I want to make sure I don't mess anything up. I don't really get this enclosed cooling system. Is it a 50/50 mix or just distilled water? Does my Alpha one drive not have a water pump or impeller? They pulled the freeze plugs last winter so there is no water in the system. Is it gravity fed like some cars or what? During my research I see people talking about this 3' or 4' cooler? How does that work and in which year did they convert to the 4"? I know all about the belt driven alternator conversion so I don't need info on that. I know these can be a gamble but I guess I'll find that out on my own. I'm just looking for general info on these motors and how much better the later versions are than the early gen. Thanks!

 

[Bt Doctur]

this motor uses a 50/50 mix of water and ethelene glycol AF. All alpha`s have a impeller in the drive to supply cooling water to the heat exchanger
and the waste water exists the heat exchanger to cool the riser on its way out.
Motors have core plugs ,.not freeze plugs and your motor has none. It has I believe 3 drain plugs in the A/F side and 1 drain plug for the raw water in the heat exchanger. The aft most one in the bottom.

Just make sure the battery is fully charged and never jump start the motor hoping the charging system will charge the battery. the charging system does not like a 40 amp charge rate.

 

[JNormV163]

Ok thanks. Im going to get a better look tonight. Do you know about the year they switched to a lager heat exchanger? Or should I just check my own? lol Boat is at my cousins place so I'm being kind of lazy on just going and checking it out.

 

[stonyloam]

with an 87 you have the larger 4" exchanger. To winterized you only need to drain the exchanger by pulling the afmost plug on the underside of the exchanger (to drain the raw water). You do not drain the the antifreeze in the engine itself. It is a pressurized closed cooling system, exactly the same as your car, except it uses a water cooled heat exchanger rather than an air cooled heat exchanger ( radiator) in your car. Yes it has a impeller in the outdrive, and the very first thing you need to do is put in a brand new OEM impeller and PUMP HOUSING after that replace the impeller every 2 years. Come on back with any other questions, we have done it all here LOL! Welcome tu the 470 Club!

 

[JNormV163]

Ok Thanks for your comment. I didn't have time to go get it yesterday but I will today. We will see how it goes!