Installing a starter on 3.7 Mercruiser, 170 HP (Ser #A592217)

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CPO1HankRCN

Cadet
Joined
Aug 28, 2011
Messages
10
Bought boat with starter missing. Have purchased a new starter and would like to know how it goes onto the motor. I do have it in place and I think the two long bolts go from the back of the fly wheel housing to the front where they are held in place by a nut (with rubber and nylon insert).
This is my first boat and working on them. I am relatively comfortable around a car or truck engine, but don't know much about the Mercruiser engine.
If anyone could also tell me where I could get a wiring diagram for the starter I would be most grateful. As the boat didn't have a batter in it either, I would also like a wiring diagram for the battery. The neg and pos aren't a problem, but there are about 6 other wires that go somewhere. I think they might go to the pos side of the battery and be grounded elsewhere on the boat.
The boat is a 1986 Sport Craft 17.5 foot and also has a Mercruiser Drive unit and transom assembly.
Thanks in advance for any help you might be able to throw my way on these two issues.
YOurs in boating
 
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dccordell

Chief Petty Officer
Joined
Apr 28, 2010
Messages
415
Re: Installing a starter on 3.7 Mercruiser, 170 HP (Ser #A592217)

The manual will give you pretty much everything you need to know to wire up the starter, as long as there hasn't been too much fiddling around with the wiring by the previous owner(s).

As far as the other wires at the battery... well, those could be a number of different thing such as power to accessories within the boat (bilge pump, blower, lights, etc..), and/or could be a main power line to a distribution block somewhere else within the boat, such as near the battery or under the dash. It's so hard to say for sure because all boats are wired differently from the factory, and it seems like after so many years and different people owning the boat, wiring is added/removed/swapped around/tapped into/etc.., so you really don't know what you have until you get in there and just start tracing wires. If it isn't too many wires, and you can see where they all go, then you should be able to figure out what wire goes where. Make a list of the wire colors and what they go to, or put labels on the wires themselves so you know what they are.

A generic wiring diagram for boats would be a good place just to get an idea of how boats should be wired (not necessarily how yours is wired though), and may help you at figuring out where all the wires go, and where they should be. Here's one that you can find on this forum, in the Electrical section, under the Stickies at the top of the forum:
http://forums.iboats.com/showthread.php?t=186986

Sounds like you might have jumped into a boat needing a little bit of straightening out first.. but that's ok. This is the best place to get it right. Just ask..
 
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CPO1HankRCN

Cadet
Joined
Aug 28, 2011
Messages
10
Re: Installing a starter on 3.7 Mercruiser, 170 HP (Ser #A592217)

Thanks to both Stonyloam and ChazzL for the information. I have been unable to download or print the manual from the sites that you gave me, but will keep trying.

I have a bracket along with the rest of the bolts, nuts, etc given to me when I bought the boat. What is the bracket for? It has two holes about the same size as the starter bolts, with a curve between the holes ( as if it were to fit around the starter case), ...... does this go on the starter bolts before I put the nuts on them? What is the bracket for..... does the slave selnoid go on this bracket? I have seen pictures of each , but never one of the starter with the bracket on the assembly nor the slave selonoid attached. I have nearly got my fingernails wore out from scratching my head, but still not totally sure where the bracket goes, what it does and why it's there. All I know that it was a part of the nuts, bolts, washers, etc given to me by the lad that I bought the boat from and I guess are apart of what he took off when he removed the starter.

I truly wish I had a picture of the starter on the motor, all bolted up and ready to go, so I could see where everything goes.

Again thanks for your help so far and I will continue looking on line, scratching my head and praying that someone has a picture of it all together that they could send me.

Also, Don,S...... I will keep an eye on the dates from here in. Thanks for that also.
 
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stonyloam

Vice Admiral
Joined
Mar 13, 2009
Messages
5,827
Re: Installing a starter on 3.7 Mercruiser, 170 HP (Ser #A592217)

That is a brace that goes on the other end of the starter. It bolts onto the starter with the two bolts that hold the endplate on, and bolts to the block. It is a major PITA to put on. Should see a coupleof threaded holes in the block where it bolts on. Here is an illustration : http://www.mercruiserparts.com/Show...nbr=10&bdesc=STARTER+MOTOR+AND+WIRING+HARNESS
 
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CPO1HankRCN

Cadet
Joined
Aug 28, 2011
Messages
10
Re: Installing a starter on 3.7 Mercruiser, 170 HP (Ser #A592217)

Hi there again. A very large thank you to ChazzL, Stonyloam and dccordell for all the above information.

I have got the MerCruiser Service Manual number 8 copied and in a binder for future reference and have used it on several occasions already. Thanks for that, it is a MUST have if you own one of these things!!!

And, like dccordell said, I did get a boat that needed a bit of straightening out, but in doing so, I am learning a lot about the boat and it's problems along with familiarizing myself with a lot of 'boat issues' that I have been reading about on this forum. It has been all 'good stuff ' and 'stuff' that I may be able to use later.

I must say, it has been an experience in itself...... just to get to know this site and to read other problems that folks are having with the same unit. I do hope that I don't encounter all the 'shortfalls ' that seem to follow the Mercruiser, 170.

Again thanks to you all, the starter is on, after may hours of pondering, skinned knuckles and a bit of profanity. I will be trying the starting up process today sometime and will get back to you folks on how that 'pans out'........
 
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