99 2 stroke 60hp stalled at 3/4 throttle?

[bikecntr]

Just bought 99 15ft key west with 60hp 2stroke. The engine starts up with no problems, slight miss at idle when under way from boat ramp. Boat gets up fine and runs well for about 10 minutes, then powers back and or stalls. New plugs, pre mixed fuel at 50:1, and engine seems to pump water well at idle and underway. I started the engine up and idled back to the dock, and then got on plane again. The engine stalled again, and then would not start for about 15 minutes. Started up again and made it back to the ramp. I do not think the alarm horn works, and am concerned about overheating or maybe needs new fuel filter? Any suggestions would be well taken!

[boats.net]

Most common is fuel restriction in boat fuel system.Plugged or kinked fuel lines, bad antisiphon valve in gas tank, plugged gas tank vent. Fuel pump bad or dirty carbs.

[bikecntr]

problem found

Well its been a while since I fixed the problem, but after 2 failed attempts at the yamaha dealer, i decided to take things in my own hands. Completely drained the fuel tank and found water in the fuel even though the dealer said they did the same. Then I installed a new Racor filter with the glass bowl on the bottom, so I could see if any water or contaminants were in the fuel. Problem solved. It is amazing that the dealer was to lazy to drain the fuel tank completely, especially when it only had 15 gallons of fuel in it. I spent over $700.00 with them for basically nothing. Lesson learned! I now run a fuel stabilizer from mercury in the fuel. It is for the ethanol and increases the octane and is a detergent to keep the carbs clean. The boat now runs like a champ!