1991 Four Winns 3.0 Cobra shuts off, starts right back up

[matthysone]

Not my boat but a coworker has a 91 Four Winns 3.0 Cobra. He states that at all stages, idling, accelerating, cruising on plane, the engine will just shut down as though the key was turned off. Says there is no sputtering or any sign the engine is fighting to stay running. Then after coming to a stop the boat turns over, starts normally and off they go as though nothing had happened. Said it didn't seem to matter whether the engine had only been running a short time or all day. Also that he always tops off his tank and this will happen with a full or not so full tank. Any list of things to check would be helpful. I was thinking fuel issue such as plugged tank vent line but the way he describes it seems more electrical in nature. Thoughts?

 

[alldodge]

Not my boat but a coworker has a 91 Four Winns 3.0 Cobra. He states that at all stages, idling, accelerating, cruising on plane, the engine will just shut down as though the key was turned off. Says there is no sputtering or any sign the engine is fighting to stay running. Then after coming to a stop the boat turns over, starts normally and off they go as though nothing had happened. Said it didn't seem to matter whether the engine had only been running a short time or all day. Also that he always tops off his tank and this will happen with a full or not so full tank. Any list of things to check would be helpful. I was thinking fuel issue such as plugged tank vent line but the way he describes it seems more electrical in nature. Thoughts?

I would say it's an electrical issue also. Check the key switch, and lanyard stop switch

 

[matthysone]

He has already replaced the key switch. I'll have him check the lanyard safety stop switch. Anybody ever heard of the shift kill switch causing this?

 

[Bondo]

Ayuh,.... Check, 'n clean the Grounds, startin' at the battery posts, 'n workin' to the ignition,....

 

[alldodge]

He has already replaced the key switch. I'll have him check the lanyard safety stop switch. Anybody ever heard of the shift kill switch causing this?

No, but there is a shift interrupter, but this would not kill the engine. I would suggest checking connectors, pull the main engine connector clean/reinstall, with engine running, wiggle all the different cables to see if something is loose. Could also happen if it looses a ground. These things are real head scratchers and it takes a lot of time most often of removing and reinstalling connectors and cables.