In reality, this problem can be caused by a variety of issues. Everything from fouled or corroded spark plug wires to debris in the gas can cause sputtering or loss of power. The first step is to identify what the cause of the problem is. The easiest way to do this is by eliminating the simplest explanation first and working your way outward until you locate the issue. The most obvious answer is fuel. Just as people lose track of time, it’s equally easy to lose track of your fuel consumption. If you have plenty of fuel, then the next place to look is the fuel filter. Hopefully, you have a spare filter with you. If not, remove the current filter and see if there is any debris you can remove. While you have the filter off, make sure there is no water in your fuel. Remember, for I/O boat owners, vent the engine box before you restart the engine. If you forget this important step, the clogged filter will seem like nothing compared to your new problem. So, if you have gas and your filter is fine, the next place to look is the spark plugs. Check them one at a time and inspect the wires while you’re there. Seriously, only take one wire off at a time and make sure to put it back before removing another wire. The last thing you need is to take all the wires off only to realize you don't know the placement order to put them back. If one or more of the plugs are fouled, do your best to clean them up and remove as much of the gunk as possible. Using a rag or loose piece of cloth, you should be able to remove quite a bit of build up. You can use a knife or similar object to scrape off large pieces of build up but be careful not to damage your spark plug or inadvertently adjust your gap. Inspecting the plug wires is as easy as checking them for signs of age such as cracking or brittleness. If you still haven't found the issue, inspect your terminals and connection points. Signs of corrosion, damage, or breakage indicate it's time to replace some terminals. Make sure you use the proper crimper when installing terminals or you risk a new problem by creating a weak point in your electrical system. The proper tool guarantees the correct crimp every time and reduces the risk of issues later on. If you have checked all the items above and everything looks fine, it is time to call a repairman.