Mercury Tracker 25 hp won't start.

[DillonWolf85]

So today I brought my boat to the lake for some fishing. Got the boat in the water and it wouldn't start. Tried pull starting it and it still wouldn't start. Replaced both spark plugs. Nothing. So I got the boat back home and checked the fuel filter and it was clean as a whistle. Went thru the whole fuel line and all is flowing perfectly. Here is where my problem is. The fuel is flowing fine up until the point where the gas line enters the engine. I sprayed some carb cleaner directly into the carburetor and the engine fires up perfectly but stalls out after about 3 seconds when the carb cleaner is all burned up. It's is the fuel blocked from entering the engine altogether? What could it possibly be? The engine is a 1998 mercury tracker 25 hp 2 stroke the engine is called a 25 el and the serial is 0g729965. Any help is greatly appreciated. Thank you.

 

[galamb]

First off, lose the carb cleaner. This is a two stroke so the only way all the moving parts get oil is if it is mixed in the fuel. Carb cleaner (or starter fluid) not only doesn't contain oil it also has a nasty habit of washing the oil stuck to the crankcase parts away causing excessive wear on the metal parts, drastically shortening the life of the motor.

Now, since you have good gas flow to the engine itself, and your experiment showed that if "fuel" got to the throat of the carb then it fired up (meaning the reeds are not gummed up), then you can concentrate on the (stuff) between the connector at the cowl and the throat of the carb.

So, there is the connector itself at the engine cowl (could be faulty or clogged), the fuel filter (clogged), the fuel lines from the connector to the fuel filter, the fuel filter to the fuel pump and then the pump to the carb - could be collapsed, blocked etc.

If those are fine then you have two final options:

1 - your fuel pump is shot (normally a perforated diaphragm) = no pressure to push the fuel to the carb, or

2 - your carb is gummed up.

When was the last time the motor was running fine? If it was a few days ago/last week then it is "more likely" a toasted fuel pump.

If it's performance has been degrading a little over the past few weeks, that may indicate the carb was getting blocked up (but would not rule out a perforation in the fuel pump bladder that got worse)....

 

[DillonWolf85]

First off, lose the carb cleaner. This is a two stroke so the only way all the moving parts get oil is if it is mixed in the fuel. Carb cleaner (or starter fluid) not only doesn't contain oil it also has a nasty habit of washing the oil stuck to the crankcase parts away causing excessive wear on the metal parts, drastically shortening the life of the motor.

Now, since you have good gas flow to the engine itself, and your experiment showed that if "fuel" got to the throat of the carb then it fired up (meaning the reeds are not gummed up), then you can concentrate on the (stuff) between the connector at the cowl and the throat of the carb.

So, there is the connector itself at the engine cowl (could be faulty or clogged), the fuel filter (clogged), the fuel lines from the connector to the fuel filter, the fuel filter to the fuel pump and then the pump to the carb - could be collapsed, blocked etc.

If those are fine then you have two final options:

1 - your fuel pump is shot (normally a perforated diaphragm) = no pressure to push the fuel to the carb, or

2 - your carb is gummed up.

When was the last time the motor was running fine? If it was a few days ago/last week then it is "more likely" a toasted fuel pump.

If it's performance has been degrading a little over the past few weeks, that may indicate the carb was getting blocked up (but would not rule out a perforation in the fuel pump bladder that got worse)....

Thank you very much for your reply. These are the same two conclusion I had come to in my own mind, but I wanted a second opinion from someone who knows what they are talking about and that's what I got. And yes, it ran just fine about 3 weeks ago. I have never taken apart the carburetor or fuel pump but I want to learn the ins and outs of this motor so I'm going to buy a service manual and attempt this on my own. I will come back and reply with my findings. Thanks again for your help and time.

dillon