OMC dies after a couple of hours of cruising

pnypwr5

Cadet
Joined
Feb 4, 2009
Messages
11
I have an 89 3.0 OMC that has recently started stalling out after a couple of hours of cruising. It has a new fuel pump and is still pumping fuel correctly( it did go out). When I check for spark, it has none. I let it sit a few minutes, with cap off, then the spark comes back and it starts right up and runs a little longer, then I have to go through the same process all over. I have replaced coil and condensor, thinking that condensor was getting hot. It is very frustrating as it keeps happening. Boat ran fine all summer and just started this in September. Could it possibly be that the points in the ignition are bad and not keeping the spark. I would like to switch out to an electronic ignition and do way with the points. Any other ideas or suggestions would be greatly appreciated.
 

chiefalen

Captain
Joined
May 18, 2008
Messages
3,598
Re: OMC dies after a couple of hours of cruising

You checked all the grounds? They must be clean. The cables good on the battery good connection there?

The wires all have clean connections?

The dizzy cap has a good connection for the rotor?

How are the wires themselves for the dizzy??
 

luv2b0at

Petty Officer 2nd Class
Joined
Jan 21, 2009
Messages
176
Re: OMC dies after a couple of hours of cruising

i had a similar problem with my 85 OMC 3.8 V-6. The problem ended up being the cooling system in general. The passages were fouled with corrosion. Don't know exactly why it affected the spark, but once I had new manifolds, risers, etc., the problem went away.
 

chiefalen

Captain
Joined
May 18, 2008
Messages
3,598
Re: OMC dies after a couple of hours of cruising

Chief sure it wasn't that you unhooked a few grounds and then when you went to hook them back you sandpapered them and then the problem went away?

Maybe just maybe the main plug is dirty inside or green inside and that needs a cleaning?

Got to be traced down but my moneys on a ground being bad?
 

chiefalen

Captain
Joined
May 18, 2008
Messages
3,598
Re: OMC dies after a couple of hours of cruising

Woa you got a kill switch on that boat bypass it take it out of the equation.

It could be the whole problem right there kills the spark it sits and you jostle it and it starts or vibration causes it to open the loop.

Here is Dons post on trouble shooting.

http://forums.iboats.com/showthread.php?t=167035
 

pnypwr5

Cadet
Joined
Feb 4, 2009
Messages
11
Re: OMC dies after a couple of hours of cruising

I will try the can of air approach when I get it back out on the water. I do know that the wires all look good as well as connections. I went over all of them as I was trouble shooting, but will recheck. I am not for sure about the killswitch, I am not aware of one, but will check for that too. I am also going to check the points and try to replace with electronic ignition. Interesting note on the cooling system and how that could affect spark. I need to check into that too.
 

moparman

Petty Officer 1st Class
Joined
Oct 14, 2008
Messages
314
Re: OMC dies after a couple of hours of cruising

if this thing has points and condenser,my two cents worth will be on the condenser being bad.That's what stores up voltage while the points are closed ,so that when they open it discharges to the coil. If its getting hot, it can act just like what your describing. Cheap replacement to see if it fixes it.Or a better fix would be to refit with an electronic ignition. mopar man:eek:
 

Rocky_Road

Lieutenant Commander
Joined
Oct 8, 2008
Messages
1,798
Re: OMC dies after a couple of hours of cruising

if this thing has points and condenser,my two cents worth will be on the condenser being bad.That's what stores up voltage while the points are closed ,so that when they open it discharges to the coil. If its getting hot, it can act just like what your describing. Cheap replacement to see if it fixes it.Or a better fix would be to refit with an electronic ignition. mopar man:eek:

Good point...about the condenser!

That could be the 'cheapest' throwing parts at your problem solution, on record.

I agree with the electronic upgrade...100%. A whole lot of potential problems, taken out of the equation...forever!
 

chiefalen

Captain
Joined
May 18, 2008
Messages
3,598
Re: OMC dies after a couple of hours of cruising

For 200+ bucks you can buy a awful lot of points. And it still might not solve his problem.

Won't help with hp and has been running this motor and many other motors for a 100 years.

Got to run down where the problem is and not throw parts at it.
 

pnypwr5

Cadet
Joined
Feb 4, 2009
Messages
11
Re: OMC dies after a couple of hours of cruising

Well I did replace condensor, and it still stalled out after an hour or so. i agree that the problem must be tracked down, but it gets difficult to track when it only happens when you are on the water and away from everything. I will try to convert to electronic ignition and do way with points, if no luck- Selling it!!! :cool: Not realy, will basically start all over with trouble shooting one step at a time........Then sell!! I do have my eye on a nice late model with no apparent mechanical pitfalls:)
 

a70eliminator

Captain
Joined
Sep 9, 2007
Messages
3,746
Re: OMC dies after a couple of hours of cruising

From your explaination
I believe this to be a heat related breakdown
you already replaced the coil good move they do break down under heat stress.
you also replaced the condenser so there's not much else in that department
being an OMC you have those two micro switches, the overtravel switch and the ignition interupter shift assist, I would be looking at them next one of them may be weak and shorting internaly under heat stress.
In case you didn't know both these micro switches will take out the spark, they are located on the starboard side shift linkage.
 

td8

Cadet
Joined
Jul 18, 2008
Messages
22
Re: OMC dies after a couple of hours of cruising

More than likely your problem is in your wiring.As for converting to a electronic ignition I wouldn't waste my money on it.Trust me I have ran everything for dual point ignitions to crank trigger ignitions on my race cars.The points ignition is by far the cheapest and easiest to work on and troubleshoot.Just my 2 cents worth.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: OMC dies after a couple of hours of cruising

When it stalls, do you still have power to the coils + terminal (with the ign. switch in the run postition)? If not, no sense looking at the distributor, it's not the problem.
If you aren't good with electrical troubleshooting with a meter or test light when out on the water, try this. Take a jumper wire with you that will go from the battery + terminal to the coil + terminal and see if it will start. That will eliminate all the wiring to the switch and back to the engine. if it does run with the jumper, at least you have an idea where to start looking.
Just follow the power from the engine, to the ignition switch, then from the switch back to the engine.
 

pnypwr5

Cadet
Joined
Feb 4, 2009
Messages
11
Re: OMC dies after a couple of hours of cruising

When it stalls, do you still have power to the coils + terminal (with the ign. switch in the run postition)? If not, no sense looking at the distributor, it's not the problem.
If you aren't good with electrical troubleshooting with a meter or test light when out on the water, try this. Take a jumper wire with you that will go from the battery + terminal to the coil + terminal and see if it will start. That will eliminate all the wiring to the switch and back to the engine. if it does run with the jumper, at least you have an idea where to start looking.
Just follow the power from the engine, to the ignition switch, then from the switch back to the engine.

When it stalls, there is no spark at all going into the ignition or coil( i assume that is what you meant) Then after a few minutes and taking the cap off, it will regain spark and start right up, then run for a while and die again. I then take off the cap and start process all over. I will take a test light out next time as well as the jumper cable, that is a good idea and will eliminate a lot of trouble shooting, depending on the results.

Thanks
 

moparman

Petty Officer 1st Class
Joined
Oct 14, 2008
Messages
314
Re: OMC dies after a couple of hours of cruising

Bubba 1235,sorry about the short cut description I gave ,I should have said when the points close ,the saturated condenser will trigger the coil,but it still didn't fix his problem,and that's what we're trying to do.Dons idea sounds great, as far as tracing the problem down.It really sounds like a heat related issue,and will require some time to trace it out.As far as the ignition ,the points indeed are cheap ,but on a setup with a lot of hours on it ,they do have an issue with wear on the points cam, bushing wear and other things that an electronic ignition would not encounter.This also is just my two cents worth,and I hope you get the problem solved cheaply ,keep us informed. moparman
 

chiefalen

Captain
Joined
May 18, 2008
Messages
3,598
Re: OMC dies after a couple of hours of cruising

You looked in the cap and it has good connection with the rotor??

Maybe the connections are worn in the cap???? Wires going into the cap might have bad connections. Bet it's the original cap. Points are closing correctly?

Whats your gap on the points just curious? The shaft is good no play in the dizzy?
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
Re: OMC dies after a couple of hours of cruising

Bubba 1235,sorry about the short cut description I gave ,I should have said when the points close ,the saturated condenser will trigger the coil,...

I have edited my post as I don't know how the condenser in the system works... but my understanding is the main purpose is to protect the points from pitting and burning.
 

pnypwr5

Cadet
Joined
Feb 4, 2009
Messages
11
Re: OMC dies after a couple of hours of cruising

thanks for all of the information everyone, I replaced the impeller, all fluids, cleaned up all the wires and connections. Took the boat out and it runs fine, no stalling. Maybe it was just getting hot due to bad impeller or just a loose connection somewhere........;)
 

Mark_VTfisherman

Lieutenant
Joined
Nov 29, 2008
Messages
1,489
Re: OMC dies after a couple of hours of cruising

Good to have a follow up.

Just a thought-an inexpensive multimeter might let you trouble shoot any other problems that come up a little better, a la Don_S' instructions. I would keep one on board your boat- I usually do. Mruphy's Law- when I have it I don't need it :)
 
Top