Engine Stalls When Attempting to Shift Into Gear

[boatgrunt]

89 OMC Cobra powered by 4.3 - Quick background...had salt water in cylinders because of bad manifolds. I replaced the old 1-piece "batwing" OMC manifolds with Merc manifolds, replaced the head gasket, clyinder heads, plugs, wires and distributer cap. In an unrelated incident, I also had to fork over $750 to have drive rebuilt. I just finally got everything back together, ran the engine for 15-20 minute increments and changed the oil twice. The engine runs and idles great and doesn't seem to be taking in any water. I pulled a plug on each side, they were dry, and the oil got progressively better looking. Two questions:

1. The oil level appears to be holding steady, and the oil looks more like oil as oppose to choclate milk each time I change it. How many times should I have to change the oil before it stops showing signs of water?

2. The engine stalls when I try to shift into gear. I don't have the linkage hooked up for the throttle - just the shifter. Could this be causing the engine to die when I try to shift into gear? If not, what could be causing this problem?

Thanks

 

[Alumarine]

Re: Engine Stalls When Attempting to Shift Into Gear

1. I've found between 2 to 4 Oil and Filter changes and the oil stays good looking. I just use cheap oil and filters when doing this.

2. Sorry don't know

 

[Don S]

Re: Engine Stalls When Attempting to Shift Into Gear

Shift cable is corroded and stiff and needs replaced. Happens to OMC Cobra's and Merc Alpha's all the time.

No, adjusting it will not cure the problem. You might get it working while you are messing with it, but after it sits for a few days it will die again.

How many times should I have to change the oil before it stops showing signs of water?

No set number of times. I have had luck with using a couple of quarts of diesel instead of oil to help get rid of the water. Run it for about 15 minutes on muffs, change filter and oil/ diesel mixture a couple of times and see how it looks.
When that looks clear, go for a hard run and check occasionally. The extra heat will burn off any leftover water.

 

[boatgrunt]

Re: Engine Stalls When Attempting to Shift Into Gear

Don - not doubting your advice at all. I've read enough of your posts to know better. Still, I like to understand how things work mechanically. How does the bad shift cable cause the engine to stall?

 

[Don S]

Re: Engine Stalls When Attempting to Shift Into Gear

It's very simple. The outdrives have a shift interrupt system. Merc uses a "Kill the ignition" OMC uses a "Kill half the igniton" to make the engine hesitate so the drive will come out of gear.
When the shift cable is stiff and causes excess resistance to the cable it activates the shift interrupt system at the wrong time and for too long and the engine dies.
With a good running engine the OMC system (aka ESA) should only kill half the cylinders, but if engine conditions are bad enough due to needing a tuneup or bad wires, spark plugs etc. they will die when the system is activated.
Incase you haven't already seen it, check out this link.

http://www.hastings.org/~stuart/cobra/index.html

 

[boatgrunt]

Re: Engine Stalls When Attempting to Shift Into Gear

Thanks Don - so, in theory, I should be able to take the shift cable off the braket (hense bypassing the ESA) and manually shift the drive into gear?

 

[Don S]

Re: Engine Stalls When Attempting to Shift Into Gear

Yep, but if you are in the water, you probably won't be able to pull hard enough to get it out of gear.
You could also just unplug the ESA module.

 

[boatgrunt]

Re: Engine Stalls When Attempting to Shift Into Gear

Don - Are you suggesting that unplugging the ESA module is a way to fix the problem or just a temporary procedure to shift the drive into gear and isolate the shifting cable as the problem?

 

[Don S]

Re: Engine Stalls When Attempting to Shift Into Gear

You don't have to disconnect the ESA connector or the shift cable, just watch it and have someone put it in gear. If that Y block actuates the shift interrupt switch when you put it in gear, there is too much resistance (aka- bad cable)