1986 Mercruiser 170 Ignition

[TheCubDriver]

I just finished taking all the components minus the block and pistons and Cam off of a Mercruiser 170 and putting it all together on a 470 Block. My question is now that it all wired up outside the boat I want to start it to make sure it runs. I got the battery connected to starter and grounded to the block.

On the wiring harness connector I've spliced holes 5,6, and I can turn the engine over when I insert 7. When 1 and 2 are connected I seem to get no spark. It seems to crank over with out a problem and sounds normal with 1 and 2 connected but as soon as I disconnect them it bogs down and wants to stop turning over.

Am I missing something? I'm hoping there is some obvious mistake in wiring that I'm missing or do I need the harness from the boat to fire it up? :facepalm:

-Jake

 

[Bt Doctur]

Re: 1986 Mercruiser 170 Ignition

quick way is to get a ballast resistor from a auto store(chrysler preferred) ,+ battery to resistor, other side of resistor to + side of coil. use a remote stat to trip the solenoid. add a water supply and go.

 

[TheCubDriver]

Re: 1986 Mercruiser 170 Ignition

It's getting plenty of spark when I disconnect the coil and ground it out its seems strong. I Believe the cooling systems is self contained.

 

[stonyloam]

Re: 1986 Mercruiser 170 Ignition

It's getting plenty of spark when I disconnect the coil and ground it out its seems strong. I Believe the cooling systems is self contained.

It is, but you still need water to the outdrive or you will ruin the impeller (in the seawater pump).

 

[TheCubDriver]

Re: 1986 Mercruiser 170 Ignition

This engine is out of the boat and the outdrive is not with it. I've added water and coolant into the exhaust jacket. Is there another freshwater source that I'm missing and where is the line?

The engine still is bogging down when the ground wires are disconnected from the harness and spark is applied to the plugs. Is there another safety switch that arrests the crank?

-Jake

 

[TheCubDriver]

Re: 1986 Mercruiser 170 Ignition

Figured it out! I didn't have the distributor in the correct position. Advanced it, and she fired right up. Thanks for all the tips!

 

[Don S]

Re: 1986 Mercruiser 170 Ignition

I sure hope you actually set the timing using a timing light and not just to the point that it runs.