470, 3.7L - Cut out switch issue? No spark to coil.

I have a 1989 Bluewater with a 470, 3.7L, 165hp MerCruiser. I had finally got the boat to were I thought it would safe and perform on the water. So last Saturday I put it in the water for the first time since I have owned it. Turned it over and fired right up. Warmed up the motor for about 15 minutes just go through everything one last time. Put it in reverse to back around the dock. Then shifted it up to forward and the motor cut out. Tried to start it after that and nothing. Opened the engine cover and pulled the coil wire. Nothing, no spark. I really didn't feel like trying to diagnose it on the water so I loaded it and took it straight to the shop. You all know shops are pretty busy right now so I thought about going to pick it up this weekend and work on it myself. So does it sound like just the cut out switch or could it be something else? While I have been working on it over the last several months I did put it in gear (forward and reverse) in the driveway (I know that freaks some of you out) and it worked just fine. The reason I did this is that I had just replaced the shift cable and wanted to make sure it worked.

Some work I have done recently that is related:
Replaced the bellows and shift cable.
Replaced the starter.
Switched to Petronix ignition.

I have ordered a new shift plate with the new style cut out switch just in case. I really didn't like the design of the old style cut out switch.

Any suggestions?

Re: 470, 3.7L - Cut out switch issue? No spark to coil.

The cutout switch grounds out the coil. If you disconnect one side of it for a quick test it you will know real quick if that's it or not.

First make sure you are not in gear. I dont advise you operate the boat like that either.

Re: 470, 3.7L - Cut out switch issue? No spark to coil.

Thanks. I am just debating wether to go pick up the boat or leave it at the shop and risk not having it for labor day weekend.

Re: 470, 3.7L - Cut out switch issue? No spark to coil.

Usually diagnosing no spark is quite easy. Depends on your electric knowledge... and skills with a meter. (Psss, and ability to follow directions ) There are simple basic tests you can do that will narrow the field quickly and easily... And we are all here for you... (Hey, if you can't blind 'em with science, baffle 'em with BS )

Personally, pick it up and save a shed load of money, have it fixed quicker, and learn how to diagnose and fix when you're out on the water and (god forbid) it does the same thing...

Chris........

There are 2 articles in the stickies I would recommend you read before making a decision... The first is about how a points ignition system works, the second is how the shift cutout works.... They are both well written and accurate. (no, I didn't write them)....

How points ignition system works.*/ 329742

http://forums.iboats.com/mercruiser...nterrupt-system-works-288089.html#post1930449

Re: 470, 3.7L - Cut out switch issue? No spark to coil.

If you can do shift cables you can troubleshoot it too. if it happened when you were shifting the switch could be stuck. too much cable throw would also affect it.