Problems with I/O Mercruiser Alpha One

[imgoing2sleep]

I have a I/O 135hp Mercruiser Alpha One engine on a 17ft Maxum boat, and today the boat won't start. For some reason the boat will not start and when it starts it won't run at idle speed. It almost seems like it's a fuel problem but the fuel gage says that I still have half a tank left. I am not very good at trouble shooting so any help would be apreciated.

[Gissert]

Perhaps you have some water in your fuel. That could very well cause the symptoms you are seeing. With the swing in temps lately, you could have had considerable condensation form in your fuel tank.

Try putting some seafoam treatment in the tank, or just flat out drain the old fuel and starting with some good fresh gas.

[Ralph Wiggum]

Go buy a bottle of isopropanol (HEET) and pour that in. It'll get rid of any water in the tank and fuel lines.

[imgoing2sleep]

Thanks guys, I'm going to give it a try and see what happens.

[imgoing2sleep]

I have added some ISO HEET but the engine is still doing the same thing. I have however notice that when I prop the top plate on the caburetor open the engine runs and idles just fine. Has anyone experienced this before?

[Valv]

The top plate is your choke, if motor is cold it should be close or partially closed, when warm it should be completely open. You might have a sticky choke body or similar.

[Surface Tension]

My first thought was the choke. It might have operated fine in the warmer temps but with the cold your choke adjustment isn't tweaked quite right or its dirty.

First thing you should do is clean the outside of the carb linkage with a carb cleaner. It that doesn't work then go onto adjusting the choke. Don't know if you have an electronic choke or one that uses bi metal springs.

You can take you a manual from your library, it'll have specific instructions on choke adjustment.

[imgoing2sleep]

Thanks guys, I found some additional information for the carburetor and will try tweaking a few things. Hopefully that helps.