3000 rpm problem

[Jason252]

Good morning everyone. Had some trouble yesterday day and I’ll try to explain as best I can. I have a 2006 175 four stroke. Started the motor and it ran amazing for about 20 min and then it started losing rpms. I try to run around 4000 but it dropped to 3000. I pulled back the throttle to neutral and tried again. Still won’t go over 3k. I shut down the motor and started back up after 30 seconds. Boat ran flawlessly for a few hours while trolling. On the way home, it dropped and would go over 3k rpms again but once shut down and restarted, it ran fine. I checked the fuel and there’s zero water. I pulled the side case and looked at the shift switch. It was completely caked in grease to where I couldn’t even see the switch. That has since been cleaned. Anyone have any other ideas before I put everything back together and try to run it? Thanks for any help

Forgot to mentions, I never received any warning lights. I can’t get into a Suzuki dealer right now for a diagnostic test because they are backed way up