Re: ’79 OMC 9.9; grommet time?

[Casey Lynn]

Ditto on what Fleetwin said.
Why take a chance on a stellar running engine?
Plus….unless you have a pyrometer it will be tough to check the running temp at WOT.
While the powerhead is off you can grease the shift linkage which I will guarantee has never been done, lubricate the throttle shaft gears (never been done) and disassemble and lube the idle stop screw assembly plus change out the fuel lines easily. Check the upper mounts while there and see if there is play in them. Clean the pan too while you’re there!
Pulling the powerhead on one of these is not a tough job at all, specially when the gearcase is off.