Suzuki DF55 1996

1st run of the season, I started real slow idled for 10 min and slowly brought to half throttle. It hesitated slightly and I thought it would for a 15 yr old 2 stroke. I visually inspect pee hole every 10-15 seconds it was clogged a couple times, I stopped and cleaned until it resumed. Ran for total of 30 min them went to full throttle and after 30 sec I heard a faint noise from motor not a loud pop but neverless it was a noise it went from 4800 rpm down to 2500 it never shut off, I throttled down to idle in gear and headed back to ramp it did not sound normal ran louder and vibrated slightly more than normal on the way back I throttled up a few times but it would not get above 2500-3000 rpm sounding bogged down. Trailered home and hooked to water it cranked fine and ran up almost to 4000 rpm neutral and in gear with no problem. I heard no beap or no warning light. Any help is appreciated.