At the risk of sounding redundant about things that most people know about, or should know about, there are 3 items that need to all cooperate for an engine to run- the engine needs to be mechanically sound, the fuel system needs to deliver fuel correctly, and the ignition system needs to spark properly.
So since these 3 things need to work- fuel, ignition, and mechanical- any problem with an engine is caused by one of them not operating correctly.
Now, it can be frustrating when an engine does not
work right, but you can usually troubleshoot which system it is. For example, if you are running at speed and the engine starts sputtering and you have an
electrical tach make sure to look at it. If the needle bounces up and down or just goes to the peg you probably have an ignition issue. If you can keep that in mind, when you have a sputtering engine just a peek at the tach can help troubleshoot the engine and save both time and
money.
Diagnosing a fuel system issue, read this but make CERTAIN you read the caveat right afterwards-
The easiest way to diagnose a fuel system issue is with a can of starting fluid. Just give it a whiff of it and see if the engine fires up. If it fires up and then dies, well you've figured out your system that is not working somehow.
The warning here is that as we all know,
2 stroke engines such as an
outboard rely on
oil in the fuel to lubricate the engine. If you use starting fluid you run the risk of
washing off the
oil in the cylinder and on the bearings. So the safest way to handle this is to get an oil squirter can and fill it with pre mixed gas:
An advantage of this type is you can even keep the engine running in an
emergency for quite a distance by giving it a squirt every few seconds.
The main issue as I see it (and as mentioned by some of the posters here) is that your symptoms can be caused by either a fuel problem, or also by the ignition coils starting to fail and when they get hot they short out. So if you give it a spritz of fuel and nothing happens you most likely have a bad coil. Sometimes you are able to trouble shoot the coil by giving it a stream of cold air from an air
compressor, works fine in the shop but on the
boat you can use a can of the compressed air used for
cleaning computers. Hold the can upside down, then spray it on the coil to cool it off. If your spark comes back you know you need a new coil.
I'm now in Wildwood. Mechanic has ultrasound cleaned the carb. Oil change. There was a concern that maybe it wasn't cooling right. Water pump and thermostat replaced. Fuel has been replaced and a new sparkplug installed.
Just took it out tonight and had the same problem. I went about 2 miles at half throttle, opened it up and ran it wide for maybe 15 minutes. Then it sputtered and died. Was able to get it restarted, went back to the dock.
Anyway, since you have an
oil change it sounds like yours is a
4 stroke. I hope it all gets figured out especially since it sounds like you've already spent some
money so make certain the mechanic actually fixes the issue but you might want to bring an oil can and a can of compressed air in your
emergency kit at least until you are satisfied the engine won't give up the ghost on you again.