2003 150 Intermittent RPM drop

[Justice22]

I have a 2003 150 which will intermittently drop rpm's while running around 3800 or higher. It will drop 100 rpm's for a split second and jump back up. I have changed the fuel seperator and the fuel filter. The RPM drop usually doesn't occur until after it has been ran awhile. For example: Run the boat at 3800-3900 for approximately 30 minutes with no problems. Stop to do some fishing. Start back up and running at 3800-3900 and it begins intermittently dropping an RPM. Any ideas?

[boats.net]

Model Number? Only 100 rpm's probably timing fluctuation.

[Justice22]

Model: SX150TXRB