Test running my Mercury 90HP (outboard)

[OneArmBandit]

When testing my outboard motor (water hookup) and getting it ready for the season...
1.) As long as water as coming through, is it okay to run it for 15 to 20 minutes, or should I limit it in this setting? (In other words, is the hose hook-up enough to properly cool?)
2.) Same question I guess, but is it okay to run at close to full throttle RPM's, or should that only be done in water?
Justin

 

[Alumarine]

As long as the muffs fit properly and you get good water flow you can run it as long as you like.
You should not let it go higher than approximately 1500 rpm and then only for a bit.
DO NOT rev it high while in neutral. Only when in the water in gear.

 

[roscoe]

And do NOT leave it unattended.
Those muffs can vibrate off and your motor will overheat in no time at all.

IF I use muffs, I secure them with duct tape.