Boat motor won’t start

[Markus1205]

My boat motor ran a few months ago just fine but now it doesn’t want to start. I cleaned the carburetor and that seemed to do the trick for a day then after that noting. I noticed that the spark plugs are soaked every time I try to start it, primed or not. Is it getting too much gas?

 

[Tassie 1]

Two stroke?
Four stroke?
Age?
Mercury?
Mariner?
Got spark?
More info required...

How long have you had it?

 

[jimmbo]

Welcome to iboats

Does this engine have a Man Overboard Switch? If so is the Lanyard in place, so the Ignition System functions?

 

[Markus1205]

It’s a 2005 mercury mariner 25 hp 2 stroke with an electric start. It has spark and it does not have a man overboard switch. I’m thinking it’s possibly running too rich. The plugs are soaked every time I start it up and has black on them. I’ve had this boat for 10 years plus and never had any problems with it up until this point. If it is running rich how do I go about fixing that or what causes it to run like that?

 

[jimmbo]

Does it have an Oil Mixing System?

 

[Markus1205]

I don’t think it does

 

[Chris1956]

2 stroke Mercs have fuel pumps driven by the crankcase pulses via a diaphragm. If that diaphragm gets a hole in it, raw fuel will flood the crankcase and spark plugs. Fuel pump rebuild kits are cheap. You might rebuild or at least inspect it.