I'm no expert but every time I fire up the boat in the driveway even at idle I get a real groaning noise from the prop strut bushing if I don't lube it with WD40 first. I don't know what that thing is made of but it doesnt seem to like the shaft turning inside it when its dry. I'd be afraid to run it at 2500 rpm for any length of time without lubing it pretty well.