yamaha 70 4 stroke no high RPM

[johnnybgood]

Have a 2013 70 4 stroke that I went to use today starts right up idles fine put it in the water and no RPM above 2500. Pulled the boat out of the water and changed the water/fuel filter and changed the engine fuel filter, plugs were not fouled. Still no Rpm, has built in tank so I hooked up an external tank with new gas put it back in the water idlers fine no RPM above 2500. Have not used the boat all summer as I was working on another boat but I would start it every couple of weeks and it all ways started right up and idled fine. Don't know what else to check any ideas out there? Still under warranty so may have to take it to the dealer rather not as they are backed up a month in work