09 4 stroke cutting out when motor is warm.

[FOX5]

Hello,

I have a 2009 Yamaha 4 stroke on my pontoon and it is in the shop right now. When the motor is warm (running for about 1 hr) the engine will cut out when you are going 15-16mph. I changed the spark plugs and checked the feul filter on the motor. Any ideas? The shop I brought it to at first said it was because the prop was not the right one. oh boy.

[boats.net]

Don't know what motor you have but could be dirty carbs or fuel pump problem.