Mercruiser 496 Mag won't start sometimes??

[talbert450r]

I have a 2007 Mercruiser 496 MAG and sometimes when I go to start the motor the starter engages and the motor won't start. This does not happen all the time but when it does it will crank and every once in a while you can hear it try to start but it won't. Sometimes it will start fine and other times it may take several attempts approx 15-20. This started happening after I hit a pretty big wake and after the boat landed it immediatly died and I have had this problem ever since.

[stonebreaker]

Check for loose wiring in the ignition and fuel systems. Also check the ground straps, a bad ground can really screw with electronic systems.

[alan white]

Sounds like a bad wire connection somewhere, since a shock appears to have caused it. Might not even be located on the engine. The problem should be under warranty in any case, considering it's brand new. You should let the dealer sort it out. Getting involved in fiixing it yourself would be pointless.
Intermittent problems are difficult to analyze. It just might be, however, the dealer has a bulliton on that problem------ or have you already gone back to the dealer?

Alan

[talbert450r]

All the authorized dealers are booked for at least 2 weeks......I was hoping it was something I could take care of on my own.

[talbert450r]

The problem is so intermitten that it may not hapen while at the dealer

[alan white]

The problem is so intermitten that it may not hapen while at the dealer

Yes, but it may be something that has happened to other engines, and the dealer would have received that information in a bulletin from the factory.
There might be another dealer besides the one you say has a two week waiting time. Anything you do to resolve the problem yourself, it would be prudent to at least tread lightly lest risk the warranty.
What is needed is a factory diagnostic and a complete wiring check--- pulling and wiggling. You may have to bite the bullet.

[alan white]

Another thought occurred, and I don't know if this applies, but is this a new engine/old boat? Is the original ignition being used? If so, there's another possible source, the ignition switch itself. It might make sense to check those connections in case the repowering (if that's what it was) involved the spade or screw terminals on the ignition switch.

[talbert450r]

New boat, I just want to make sure The problem is not bad fuel or water in the fuel because the warranty won't cover that.

[alan white]

That sounds simple enough to check. Water in the tank might well have jumped when the boat did. Alcohol (and I'd wait for consensus on this) added to the tank might clear it out if it made it to the carburator bowls (if you have carbs-- I don't know the engine). Is there some reason to suspect water in the gas?

[Captain RAH]

Electrical,more than likely it is loose wire, usually if it is bad gas it wouldn't start in my experiences, until you put in the gas treatment or some a little alcohol to evaporate the water, note just a little alcohol. Troubleshoot starting with the battery, then relay, check relay with an ohms meter. Make sure the relay is good by reading with meter. Then continue on with a visual inspections of wires going to engine.

I would let the dealer check it out since it is under warranty.
That is what you paid for...
happy troubleshootn