2013 Mercury 250 Pro XS Optimax - opinions on this issue please

[TraceF3]

2013 with 418 hours, new to me. So I am running along at 4800 rpm, everything seems to be perfect. 17 psi water, 129 degrees water temp, suddenly the motor falls off about 3 or 400 rpm for a few seconds.

At first I thought I'd run through shallow water and drug the skeg a little. But then it does it again a few minutes later. Total of 4 times in a 15 minute ride. only falls off for a few seconds and then right back to normal.

New Racor, clean bowl, I drained the gas (60 gallons) and took it to haz mat disposal. Fuel is fresh and new.

Where do I start?

Thanks in advance!

[25two.stroke]

Things I have seen with those motors that cause similar issues to what you described:
Bad TPS
Bad Fuel injector
Bad air injector
main engine voltage fluctuation

Just in personal my experience as a mechanic I have seen those issues with 3.0L optimaxs cause fluctuations in rpm while cruising.

[Jim Speros]

I would suggest getting it serviced , Read codes if any. Get it caught up on scheduled maintenance.

25two.stroke shared possible causes.

Additionally I always advised my customers not to use it if it is not running properly. A bad injector with the exact wrong mixture can do major damage to engine. It could be something that doesn't damage just loses power. Or it could be doing damage every time it loses power. No way of knowing for sure.