Idle runs over 2,000 rmp when warming up

[tapedeck]

I have a 2018 ruckus. Air box delete, CDI, exhaust etc. The engine/carb is stock. The issue I'm having is when I start it up it's in high Rev with rpms over 2,000. After 5 minutes it calms down, stops vibrating, and rpms go down. It runs pretty good, but I can't figure out what is causing the rpms to Rev high until it warms up?

I decided to change fluids, oil, spark plug, and possibly re-jet the carb. While doing so, I played around with the Idle screw, but it had little effect on dropping the rpms when warming up. I also noticed the spark plug was black and had some oil on it so it's running rich.

Should I re-jet the carb to eliminate the issues with the high rpms and running rich, or am I missing something that needs attention as well?

I'm not sure if this forum is still very active, so thanks for any responce and any help figuring this out.

[Baizy]

tapedeck that honestly sounds like it's working as it should. On cold starts the idle enrichment valve is going to dump some extra fuel in for the cold start and that can have the effect of revving up the engine, the fact that it comes down to 2000 after it's warm means the enrichment valve is working and the idle is set correctly. I personally wouldn't worry about it one bit. I might worry about crazy rattling, but not a high idle that settles once warm.