1994 OMC 5.0 cobra will not start or run in the water...

[heiliges]

Well guys, after a ton of work on my new-to-me 1994 Four Winns 190 Horizon. I was ready to take it out on the water for memorial day weekend. To my utter dissappointment this weekend proved to be more of a disaster than the sheer enjoyment I thought I had coming to me. The boat run fine out of the water, at home. Unfortunately its not really designed as a car. When I get to the ramp though, it turns, tries to fire off and immediately stalls. I pull it out of the water on the ramp and for some strange reason it starts right up. I set the idel waaayyy up, like 2000 rpm and it will start in the water, but getting it into gear is next to impossible, and when I can get it to go forward and not stall, it will only idle along, even at full throttle. Any suggestions or assist is greatly appreciated, bout ready to give up on this thing.
502ACPMDA is the model of the engine.

 

[Don S]

Re: 1994 OMC 5.0 cobra will not start or run in the water...

Have you set the timing per spec? Proper degrees at the proper rpm? With a timing light?

 

[heiliges]

Re: 1994 OMC 5.0 cobra will not start or run in the water...

I have done nothing with timing since it runs. Would this have slipped out for some reason?

 

[Don S]

Re: 1994 OMC 5.0 cobra will not start or run in the water...

What work has been performed since it worked properly.

 

[heiliges]

Re: 1994 OMC 5.0 cobra will not start or run in the water...

Seems like everything. I fried the ignition system so I replaced Ignition Coil and changed the BDI control module to a pertronix module along with all spark plugs. Supposed to adjust timing as needed automatically as far as I understand but maybe not. Anyways, starter went on me the other night so I replaced that and I have replaced the impeller on the water pump. Not to mention I replaced a major portion of the stringers below deck, cleaned the fuel tank, and put on a new deck. I have done so much to this thing to get it to be perfect and yet I still have problems on the water.

 

[heiliges]

Re: 1994 OMC 5.0 cobra will not start or run in the water...

ok, read somewhere that this coule be linked to a fuel starvation issue. When I redid the flooring and cleaned out the tank and put it back in. I got a new fuel line with one of those bulbs on it. Seems like there is always air in it and I have to pump it before I run the engine. Would this be normal or should I remove this and get a straight line without the bulb? Or am I dreaming that it would be so simple to resolve.

 

[heiliges]

Re: 1994 OMC 5.0 cobra will not start or run in the water...

ok, so I did the fuel pressure test to no avail, everything checks as far as fuel is concerned. Read about the diode fix for the pertronix electronic module replacement and think I blew my ignition solenoid when I put it in. All I get is a click at the box connected to the riser. Even after I removed the diode fix. Sooo, another 25 bucks today for one of those. Will get it running again on dry land and then go from there. Anyone else have any thoughts on what would make this thing run fine on muffs and then do nothing in the water?

 

[Don S]

Re: 1994 OMC 5.0 cobra will not start or run in the water...

Do you leave the throttle/shift lever at idle in neutral when you start the engine?

 

[heiliges]

Re: 1994 OMC 5.0 cobra will not start or run in the water...

nuetral yes, idle no. It will not start without some priming even on the trailer.

 

[full stringer]

Re: 1994 OMC 5.0 cobra will not start or run in the water...

after all of that work how long did the fuel tank sit empty or half full? i had a similar problem and it ran just as u said great on the muffs but not in the water. turned out to be i had water in the fuel tank. reason was the boat sits level on the water slightly tilted back and it sits nose down a bit on the trailer. the water rushes to the rear of the tank when boat is in the water and will run towards the front of the boat when on the trailer. i jacked the nose up as high as i could drained 5 gallons of gas into a container and checked the fuel in seperate glass container and water was sitting on the bottom plain as day. i kept on doing this until there was no more water present. the boat ran perfect after that. hope this will help you. good luck man.

 

[Joshua Nichols]

Re: 1994 OMC 5.0 cobra will not start or run in the water...

nuetral yes, idle no. It will not start without some priming even on the trailer.

I know since you said this.. We can assume it has a carb.. Not fuel injection.. Correct? I am just making sure..

I guess if it was fuel injected, it wouldn't run at all with the pertronix stuff on it.. IDK?