1988 Raven 3.0 Mercruiser NO SPARK!!!

[Danny80]

Hello all!

I have a 1988 Raven with a 3.0 litre mercruise I/O motor. I had the boat running last year most of the summer - then one day it decided not to start. I messed with it for a few days at the end of last season - then just put it away for winter. Got it out of the garage yesterday - hoping that it just needed some time off - but I am still faced with the same problem. I have replaced the coil, cap, points, condenser, and wires - still getting no spark. Last year, I did crank the motor over a few times with the points not properly gapped - could this have damaged brand new points? I have plenty of power at the coil with the key on. I pull the coil wire off the distributor cap, hold it away from the block, crank the motor over - get nothing. I have tried the same with the plug wires - absolutely no spark. The motor cranks nice and fast - just will not ignite! Any help would be greatly appreciated!! Thanks in advance!

 

[Haut Medoc]

Re: 1988 Raven 3.0 Mercruiser NO SPARK!!!

Well, if the coil is properly connected & you have sufficient voltage at the coil....
But nothing comes out....
I would either test the new coil & verify that is is OK or get a new one.....
One thing I will say is have you looked at the shift interrupt switch to make sure it is not stuck.....
It will never start if that is the case......​

 

[Danny80]

Re: 1988 Raven 3.0 Mercruiser NO SPARK!!!

There is a purple wire going to the positive side of the coil and a black wire and grey wire going to the negative side of the coil. The coil was brand new, out of the box yesterday. Kill switch is not engaged. Is the grey wire the tachometer wire? I have read in other posts to remove that wire, what would that do?

 

[Haut Medoc]

Re: 1988 Raven 3.0 Mercruiser NO SPARK!!!

Yup, the result will be that your tach will not work.......
Are you sure that the shift interrupter switch is not stuck?
Not the lanyard, but the switch that is on the shift plate.....
Have you looked at the pointsto see if they are functioning normally.......​

 

[Coors]

Re: 1988 Raven 3.0 Mercruiser NO SPARK!!!

He hasn't verified voltage getting to coil, etc ?

 

[Bt Doctur]

Re: 1988 Raven 3.0 Mercruiser NO SPARK!!!

Try this to narrow it down in case the points are grounded out,remove the wire from the points,supply power to the + side of the coil (key on)and scratch the wire from the points across a ground.
spark: wire to points or points grounded out.
no spark: remove all leads from the + side, jumper from the battery to the + coil side and retest.
spark: no power to coil or bad /grounded tach
no spark : bad coil

 

[Danny80]

Re: 1988 Raven 3.0 Mercruiser NO SPARK!!!

So what exactly does it mean if the wire to the points or the points are grounded out - what would cause that? What is the fix? Also, could someone breifly explain to me exactly how a "points" system works?

 

[Danny80]

Re: 1988 Raven 3.0 Mercruiser NO SPARK!!!

How many volts should I be getting to the postive side of the coil with the key in the "on" position? When cranking? Should I ever have voltage on the negative side of the coil?

 

[Bt Doctur]

Re: 1988 Raven 3.0 Mercruiser NO SPARK!!!

less than the battery voltage because there is a resistance wire in the harness.
The wire from the coil goes to the dist. housing. it has a rubber grommet to protect it. if it grounds out ,the points will be useless.when the points are closed the coil charges, when they open the field collapses and spark is produced.(condensed version).on some versions there is a wire coming off the solenoid that will supply battery voltage to the coil when cranking only.
Do the test in the above post and get back with some results.

 

[Danny80]

Re: 1988 Raven 3.0 Mercruiser NO SPARK!!!

Will do - thanks!

 

[Danny80]

Re: 1988 Raven 3.0 Mercruiser NO SPARK-grounded wire??!!!

Re: 1988 Raven 3.0 Mercruiser NO SPARK-grounded wire??!!!

Ok, I performed the test above. Removed the wire from the points, turned the key on and scratched wire against different grounding points - got sparks! I removed the grey wire from the negative side of the coil - and was still getting sparks from the black wire. Apparently this means it is grounded out? But where? the wire is only 6-10 inches long - and is not nipped or cut anywhere. I am still at a loss!

 

[Bt Doctur]

Re: 1988 Raven 3.0 Mercruiser NO SPARK!!!

Might be a bit of confusion with the spark.when you ground the black wire you will have a spark at the wire end. when you do ground it you should have the spark coming from the coil tower (plug wire from here to the center of the cap)also. grounding the black wire and having no spark from the coil tower would mean a bad coil.

 

[Danny80]

Re: 1988 Raven 3.0 Mercruiser NO SPARK!!!

So I need to ground the black wire and look for a spark from the coil plug wire? Should I pull the plug wire off the cap, or off the coil?

 

[Danny80]

Re: 1988 Raven 3.0 Mercruiser NO SPARK!!!

The coil was brand new, out of the box on Saturday. I did get it from the autopart store vice a marine parts store - is that a big deal?

 

[whywhyzed]

Re: 1988 Raven 3.0 Mercruiser NO SPARK!!!

The coil was brand new, out of the box on Saturday. I did get it from the autopart store vice a marine parts store - is that a big deal?

The coil is one of the few things where you can get away with automotive part - no difference.