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OmC Cobra 57 with points running Bad

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fullthrottle63

New member
"Greetings to everyone,
I hav

"Greetings to everyone,
I have a 1989 OMC Cobra 5.7 that runs bad. When I uncovered the boat this season and changed the oil and filled the empty gas tanks, it's started right up and purred like a kitten. I figured I should give it a tune up for the heck of it. I have a prestolight ignition. I changed the plugs and gapped them, changed the points, condenser and router. I also changed the rusty coil with a Sierra Part #18-5437. I gapped the points at .0016. One page of the OMC manual it states.0016 gap and another page stated .0018 gap. I started up the engine and once again, it purred like a kitten up to 3,000 rpm with the water muffs on. Later on that day, I started up the engine and it ran like crap. It wouldn't idle or run past 1,200 rpm with the throttle open. It's getting plenty of gas. I checked the plugs and they look fine. I cranked the engine over and grounded out a spark plug. It was orange in color. Next I checked the points again to see if they moved. It still was set at .0016, next I reset them at .0018 and it ran even crappier. Not sure what to do. is it the wrong coil? It states it uses an external resister, allthough I don't see one. Am I better off just buying a points coversion kit with a flam thrower to solve the problem?? Help!!!!!"
 
"Before you go with electronic

"Before you go with electronic read this post
http://www.marineengine.com/discus/messages/12488/218065.shtml

OMC uses a resistor wire instead of ballast resistor. This may sound dumb but are you sure all the plug wires are plugged in and are they in the right fire sequence? Did you try setting the timing after changing the points?

Also try unplugging the ESA module incase it's gone defective or is being activated at the wrong time. It has a 2 wire plug and a 4 wire plug, unplug the 2 wire plug (purple and gray wires)."
 
"I wonder if you cleaned any o

"I wonder if you cleaned any of the filters, the one at the fitting that enters the carb, the one in the fuel pump if you have one there. You have a fuel / water separator? Dump it in a clear container. What do you see after a hour?

Of course, you should check to see if all the wires are on the right plug, check to see if the weights in the dizzy are moving freely, and see if the condensor wire is not grounding out.

Make sure the rotor is getting good contact on the bottom of the cap, and the cap is on right, and tight.

Time the motor, make sure it's right.

Maybe you may want to pull the anti-syphin valve and check it's not sticking and that there is no clogged up screen on the bottom of the fuel pickup screen.

I always store my boat with a full tank.

Good luck !"
 
"The spark plug wires are corr

"The spark plug wires are correct. No, I didn't check the timing, because I didn't turn the distributer. My timing lite is bad and I ordered a new one from Summit today. I would like to check it to ensure the engine runs at peak performance. I'll try unpluging the ESA module. Being new to OMC, I'm guessing the ESA retards the ignition for shifting purposing. I'll look for the location of the ESA in the manual.
i checked the fuel suply and there's no problem."
 
"The ESA (Electronic Shift

"The ESA (Electronic Shift Assist) is a module that actually pulses the negative side of the coil, momentarily grounding it out, effectively causing a miss, the RPM's drop making it much easier to come out of gear. In the pic below the ESA module is located on the back side of the shift bracket shown (missing in this pic)

285267.jpg
"
 
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