cannot reach WOT

[carolina]

1990 Yamaha 200HP that I cannot get to reach WOT.Idles rough and only reaches about 4500 rpm's and normally reached about 5200 to 5300 rpm's. Also idles rough. Recently got new fuel and treated with Seafoam as usual. Load speed is fine. Did surge some as I reached upper RPM's. I know gas is the obvious culprit but what about plugs as a problem.

[jb123]

if you have ANY question about the plugs, change them.....and then clean the carbs.

[carolina]

Haven't changed them in two years but they've seen very little use. I'll look there first