1986 4 winns 3 litre 170 hp starting running issues

[rngale]

1986 mercruiser 3 liter 4 cylinder. Starts hard warm or cold at times lack of power occasionally. Points set. There is a control box on side of engine that seems to be hooked to the closed cooling system. Solenoid clicks but not the starter now. Was wondering if anyone ever had the primary solenoid fail at times? Have not removed either the solenoid or the starter yet.

 

[Bondo]

Re: 1986 4 winns 3 litre 170 hp starting running issues

1986 mercruiser 3 liter 4 cylinder. Starts hard warm or cold at times lack of power occasionally. Points set. There is a control box on side of engine that seems to be hooked to the closed cooling system. Solenoid clicks but not the starter now. Was wondering if anyone ever had the primary solenoid fail at times? Have not removed either the solenoid or the starter yet.

Ayuh,.... For the sake of Clarity,... You Don't have a GM based, 3.0l motor,....

You have Merc's own, 3.7l,... aka; the 470....

 

[natemoore]

Re: 1986 4 winns 3 litre 170 hp starting running issues

I'm pretty sure that the 470 has two solenoids, one mounted on the side of the block port side forward, and one located right on the starter itself. Not sure which one is called "primary" or "secondary." But solenoids are an easy part to bypass in troubleshooting.

 

[stonyloam]

Re: 1986 4 winns 3 litre 170 hp starting running issues

There is a control box on side of engine that seems to be hooked to the closed cooling system.

That is your water cooled voltage regulator and is cooled by the raw water coming in on its way to the heat exchanger. The solenoid on the side of the block is your slave solenoid, and yes they occasionally do fail. Here is the manual for your engine: http://boatinfo.no/lib/mercruiser/manuals/mercruiser8.html#/0

 

[rngale]

Re: 1986 4 winns 3 litre 170 hp starting running issues

There are 2times solenoids the one on the block I question because it looks original. The starter is new. I also suspect a fuel issue. I've looked up the pump and it appears I have a carter type that may contain a filter inside it.

 

[Don S]

Re: 1986 4 winns 3 litre 170 hp starting running issues

Here is how you can test your starting system http://forums.iboats.com/showthread.php?t=167035

Here is the wiring diagram for your engine.

View attachment 3.7 wiring diag 8.pdf