Mercruiser 470 engine out of the boat...how to start?

[Blueghost924]

Hi, I have a Mercruiser 470 (3.7) 1982'ish engine that's currently not installed in my boat (it's on a pallet in the garage). The reason it's not installed is because I bought it from a local shop and haven't put it in the boat yet. Anyway, I want to perform some minor tuneup and maintenance work on it, then start it up and time it. How do I go about starting up this engine outside the boat? I have a fresh deep cycle marine battery (with over 600 CCA). I've also removed the ignition switch from the console in the thoughts I would have to somehow wire it up to the harness connector on the engine to start it. I've also seen a Youtube video where another guy has a set of wires connected to the harness connector at the engine to start it up.

Also, with the battery - I believe the shop may have had the battery red cable connections wired to the slave solenoid, and not to the starter solenoid. Does that make sense? I was thinking that the red lead from the battery should be connected to the starter solenoid. When I bought the engine, there was (or is actually) a red battery cable lead already attached to the slave solenoid.

I REALLY need to get a Saloc manual....

 

[achris]

Re: Mercruiser 470 engine out of the boat...how to start?

....I REALLY need to get a Saloc manual....

NO, you DO NOT!!! What you REALLY need is the factory manual. Seloc will lead you down the garden path, then dump you there... Literally up the creek without a paddle. The second worse manual available...

Your proper Merc engine manual.

As for starting... Connect battery + to the big post on the Slave solenoid, connect battery - to any bolt on the engine block, connect fuel to the fuel pump, connect water to the inlet side of the heat exchanger. Now install a short link between pins 5 and 6 (this turns the ignition system ON). To start I would use a remote starter switch hooked up on the slave solenoid (between the red battery lead and the small yellow/red lead on the solenoid).

Chris.....

 

[Bt Doctur]

Re: Mercruiser 470 engine out of the boat...how to start?

chris, no cables are attached to the slave solenoids. we need to know if he has the ford or GM starter. ford uses a standard sized ford solenoid
and GM uses a slave type.

 

[Blueghost924]

Re: Mercruiser 470 engine out of the boat...how to start?

Thanks for the replies to both. With my setup, I don't see any solenoid on the starter at all like you would expect for an auto- I've looked hard for one! Between the starter and the voltage regulator is the slave solenoid. Since there was a red cable already attached to the slave solenoid (with the other end free), I assumed the battery (+) attached to the slave solenoid.

 

[Bt Doctur]

Re: Mercruiser 470 engine out of the boat...how to start?

 

[Bt Doctur]

Re: Mercruiser 470 engine out of the boat...how to start?

looks like the ford solenoid. The foward most post takes a battery cable and the rear post has a battery cable going to the starter
The small lug foward should have a yellow/red stripe, rear small lug may have a brown or brown/white going to the neg side of the coil.

 

[Bt Doctur]

Re: Mercruiser 470 engine out of the boat...how to start?

Boatinfo - The library, containing manuals, brochures and other technical documents from the last hundred years! view and print only.

 

[Bt Doctur]

Re: Mercruiser 470 engine out of the boat...how to start?

 

[Blueghost924]

Re: Mercruiser 470 engine out of the boat...how to start?

Thanks for the further information. There isn't a solenoid on this starter (I've replaced many a starter/solenoid in cars). I thought it was weird at first, but I was thinking maybe it was designed that way. Or it could be that the solenoid is missing from my starter? I'll try and get a picture of it and upload.

 

[Bt Doctur]

Re: Mercruiser 470 engine out of the boat...how to start?

As far as test running the motor, place a jumper from the front terminal of solenoid ,where you connected the battery cable to the + side of the coil.
take a short jumper or suitable tool to jump between the battery cable lug and the small lug with the yellow/red stripe wire. That will activate the solenoid.

 

[Blueghost924]

Re: Mercruiser 470 engine out of the boat...how to start?

Thanks Bt Doctur. Once the engine is running, I assume that removing the jumper will shutoff the engine?

 

[Bt Doctur]

Re: Mercruiser 470 engine out of the boat...how to start?

 

[Bt Doctur]

Re: Mercruiser 470 engine out of the boat...how to start?

correct, remove the jumper to the coil and motor will stop

 

[Blueghost924]

Re: Mercruiser 470 engine out of the boat...how to start?

I tried to upload a couple of pictures I just took of the slave solenoid and starter combo, but the upload failed. But looking back at the diagrams you posted above, it is DEFINITELY a Prestolite starter motor. There's a thick yellow wire from the Prestolite starter going to a lug on the right side of the slave solenoid.

 

[Bt Doctur]

Re: Mercruiser 470 engine out of the boat...how to start?

I use photobucket,free and easy

 

[Blueghost924]

Re: Mercruiser 470 engine out of the boat...how to start?

 

[Blueghost924]

Re: Mercruiser 470 engine out of the boat...how to start?

I got the first picture to upload.

 

[achris]

Re: Mercruiser 470 engine out of the boat...how to start?

View attachment 226348

As I said, the battery cable goes on the solenoid, NOT the starter motor...

 

[Blueghost924]

Re: Mercruiser 470 engine out of the boat...how to start?

The other thing I was thinking about earlier today are the 2 black neutral safety switch wires at the back near the coupling...and if they need to be shorted out to each other prior to attempting to start the motor.

 

[Bt Doctur]

Re: Mercruiser 470 engine out of the boat...how to start?

neutral safety takes place in the control box, might be looking at the trim wires