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  Topic Review (Newest First)
10-08-2012 04:11 PM
Re: Mercurey 9.9 Bigfoot HELP!

Do a search for a KD Spark tester tool, less than $10.00, it will verify if the spark is there.
The old GM shop manual method of testing Solid state iginition was " Substitute a known working component" , not always helpful advice. There are also Baja filters for $15.00 that will separate water from the fuel. Both items are handy to have, and may narrow down the the area of interest. I would also pull the plugs, and clean and gap them or replace them. The condition of the plugs may give some hints. The 9.9, at least mine has a timeing belt. worth a look see or a bad tooth or what ever.

10-01-2012 08:50 PM
Re: Mercurey 9.9 Bigfoot HELP!

If you take the suspect components to a good dealer they may be able to test them for you. As mentioned, double check all connections. One one of my motors the "Dead Man's" switch had shorted, yours could be an intermittent short? I have heard of the ignition coils partially failing after they heat up, maybe a test would show it?

Paul T
10-01-2012 07:30 PM
Re: Mercurey 9.9 Bigfoot HELP!

Most likely is corrosion on a connector. CD unites are generally (throughout the engine universe) pretty darned reliable. Trigger units aren't as reliable. Call a good busy dealer's parts department and see what they're selling a lot of, that will tell you if you get to the "just throw parts at it" stage.
10-01-2012 07:09 PM
Re: Mercurey 9.9 Bigfoot HELP!

I did a bunch of diagnostic stuff today and I think I've narrowed the problem down significantly.

The engine dies suddenly, indicating an electrical ignition problem. This idea is supported by the fact it seems to happen when the motor has been runnung a moment. Heat makes electical stuff do wonky things (expand and contract etc.)

If it was gas I reckon the death would be slow with more hunting going on in the idle. Not to mention I use sta-bill treated ethanol free gas, and i just cleaned the carb last month.

I used an indicator light to test the wiring going to the ignition coil and they tested fine untill it died then it read nothing, so the problem is before that.

I guess I could just throw parts and it... CDI, flywheel coil, pulser etc... but what is most likely I wonder?

I know that the CDI is a common problem in other vehicles... but I know the trigger or pulser or whatever its called is cheaper.

09-30-2012 04:56 PM
Re: Mercurey 9.9 Bigfoot HELP!

I've got an 04 big foot on my Mariner. I'm not exactly sure what you are asking. When running normally, there is a water outlet on the starboard side of the engine case. I've had some issues with mine not running, all associated with e 85 and/or water in the fuel. The carb is relatively easy to remove. I'd suggest you remove the carb, and clean all the jets and passages. Alcohol in e85 will absorb water and do odd things to the brass jets. A failed head gasket will result in oil or water being drawn in to the cylinder, resulting in blue or white smoke from the exhaust. The amount of smoke will be relative to the size of the head gasket failure, but will be VERY obvious. Water squirting from areas other that the starboard engine housing COULD be from a blocked passage. There are several online parts suppliers which provide some good diagrams of systems, try a search engine.
09-30-2012 04:08 PM
Re: Mercurey 9.9 Bigfoot HELP!

Picture or parts diagram showing were the water is coming out? Sounds like it may be a fuel related problem if using the choke makes it run for at least a little while. If the plug is wet it may be flooding, if dry, maybe starving. Maybe the float is stuck up or down? You could try gently tapping the carb with a plastic hammer or screw driver handle.

Paul T
09-30-2012 01:11 PM
Mercurey 9.9 Bigfoot HELP!

Hello, haven't posted in a while... been sailing. nuff said.

The other day I go to take my son for a sail and as I'm motoring away from the slip the motor dies. I cant get it started again before I drift to a bulkhead and tie off temporarily.

After a little messing about I get started at full choke and 1/4 throttle I then settle to idle and let her run for a moment.

Checking around I notice some water coming out of what looks like the shaft above the water line, and there seems to be some oil residue with it.

I slowly got back to the slip and tied up. so it dose work for at least short jaunts. like 150 yd.

freshly cleaned carb, new fuel filter. Do I now need a new head gasket? Help!

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