Hey guys,

I have purchased a Mecury motor used earlier this season.  It has run great all year.  I was out on the lake last weekend and it started giving me problems.  I don't have a manual for this motor and I am pritty sure it's from some time in the early 90's.  

This motor is a pull and go model.  Meaning there is no nuteral or reverse.  So I start the motor up like normal and with a couple of pulls it goes.  Then after a few minutes it will stal on me.  If I don't increase speed then it will go longer without staling.  

I think it may be water in my gas tank or in my gas can.  My father said it could be the plug.  So what should I check first.  Also I am woundering if they make a gapless plug for a 2-cycle motor since I don't have the manual to get the gap specs. Has anyone done this to there 2-cycle?

I am opean to your guy knowlege thank you.

Sounds like it could be a fuel supply problem, possibly a clogged filter, or some type of blockage between the tank and the carburetor.

Disconnect the fuel line at the carburetor to see if you get a good flow.  If it's a drip, drip, drip, you'll need to change the filter or purge the system.

Any water or other contamination will settle in the bowl of the carburetor, and cause rust or corrosion problems which can block jets and other passages.

Do nothing more than you can do with confidence.  

Trying to tackle something beyond your abilities will end up costing you more in the long run.

Ok thank for the advice. So you don't think it's water or a plug then? What do you mean by purge the system.  I keep Stabil in my fuel and I ran Sea Foam a few months back.  I've never done much work on motors so I am brand new is changing filters hard?

By purge, I mean to get everything that holds or carries fuel cleaned out.

I don't know how the fuel tank is vented.  If there is a problem with air getting into the tank as fuel is burned off, it will restrict the flow of gasoline.

I have that problem with my riding lawnmower.  It has a tiny opening in the center of the gas cap, which is below the seat.  

Eventually dust clogs the opening, and after running the tractor for a half hour, it will stop running because it isn't getting fuel.  Clean out the opening with a fine wire, and voila, problem solved.

I doubt it's the plug, but it will only cost a few bucks to find out.

The key to me is that it runs longer at slower speeds.  That is classic of a reduced fuel supply problem.  

If it is, you'll experience the following.

If, after the motor sits for a few minutes, it will start and run normally, then gradually slow and stop, as the carburetor runs out of gas.

Ok I see.  My vent is also on the top of the gas tank cap.  It is sealed by gaskets and you turn it to opean it more or less I usally have it fully opeaned.  I am going to check the fuel line, Plugs and gas this weekend I hope.  How would I purge everything the motor is so small.

Hey guys I wanted to let you know that I fired up the motor in the trash can and there was no problems.  So I will be headed out fishing with robby Z on Fri.  I hope there will be no problems.  I'm sure there won't be.  I actually checked the gas tank vent and cleared that.  So I think that the depressurization  may of been the problem.