Motor stalled on the water while in gear.

[fulano]

Merc 3.0lx serial number: 0k006992
Alpha One serial number: 0k077388

Hi Guys,

So, we went out yesterday, and the boat stalled out while we were driving

Ok, let me describe the symptoms, and hopefully you guys can point me in the right direction

The motor always fires right up, I mean instantly. Pump the throttle once and just barely turn the key and I swear you can't even hear the starter, it fires up on the first crank even if it's been sitting for a couple of weeks.

Yesterday it fired right up as usual. We get out of the no wake zone and punch it. As we were cruising I hear the engine occasionally "missing" not really sputtering of anything, it was running smooth, but kind of just cutting out for a split second. It felt like a miss, but I was looking down at the gauges while this was happening, and I saw all of the gauges go off for a split second.

Then while approaching a beach I throttled back a bit and the engine stalled. I couldn't start it back up, even pumping the throttle. Thinking that this must be electrical, I pulled off the engine cover and looked at that switch on top of the valve cover (interruptor switch?) and it appeared to be normal. I moved the throttle to the reverse/forward/neutral positions and it looked like it was working as it should. I tried to start it again and I could hear it wanting to start but it wouldn't. (maybe I flooded it?) I pulled off the spark arrestor and cranked it again and it started up. I drove slowly over to the beach and shut the motor off and beached it. We stayed for about an hour. We fed the kids and shoved off. I kept the engine cover off, and started the engine with no problem, then we headed back to the marina and about 3/4 speed for 5-10 minutes. No problems. about 5 minutes at no wake speed. No problems. shut the engine down and brought the trailer. Started it up again and loaded the boat with no problems.

So that's where I'm at guys. An intermittent problem. I'm thinking it's electrical maybe? I saw a couple posts about the purple wire going to the coil that gets too hot inside the harness. I guess I can start there. But if anyone has had a similar problem or if you have any suggestions, please let me know.

Thanks.

 

[airshot]

Re: Motor stalled on the water while in gear.

First thing I would do is go thru all electrical connections, very possible some corrosion somewhere. Clean all connections with a wire brush until shiney. This includes the battery connections, if using wing nut connections, use a pair of pliers to be sure they are tight !!
Be prepared to spend a day getting to "all" your connections.

 

[fulano]

Re: Motor stalled on the water while in gear.

I was thinking the same thing. I'll have to redo all the connections. I want to heat shrink everything i can too. So does this sound like an electrical problem to you?

 

[Don S]

Re: Motor stalled on the water while in gear.

Could be something in the fuel system as well.
As an example, a plugged tank vent would create a vacuum in the tank and no gas to the pump. Then with the engine off, the vacuum goes away and the engine starts again.

 

[fulano]

Re: Motor stalled on the water while in gear.

Could be something in the fuel system as well.
As an example, a plugged tank vent would create a vacuum in the tank and no gas to the pump. Then with the engine off, the vacuum goes away and the engine starts again.

Thanks Don,

I was thinking it could also be fuel, I have read alot about the anti-siphon valve problem. I just leaned toward electrical since the gauges would cut out for that split second miss.

Does the interruptor switch cause the gauges to cut out? I never thought to test that.

 

[Don S]

Re: Motor stalled on the water while in gear.

Forgot about the gauges cutting out. Neither fuel or the shift interrupt switch will kill the gauges.

 

[fulano]

Re: Motor stalled on the water while in gear.

Hmm,

On my boat, The positive terminal of the battery goes to the starter, and all other 12v power else is "t-tapped" off the starter. is this normal?

Those connections look pretty crappy.

 

[Don S]

Re: Motor stalled on the water while in gear.

Hmm,

On my boat, The positive terminal of the battery goes to the starter, and all other 12v power else is "t-tapped" off the starter. is this normal?

Those connections look pretty crappy.

Clean them up, and tighten them down. Throw the wing nuts away and use regular SS nuts and tighten them down with a wrench.

After you fix the obvious problems see if you still have the problems.