[Capt. Debbie]

Read the Mfgrs manual. Some O/B do not want it fogged.

Also draining the carbs that technique dry out the seals over time.

I had a Merc 9.9 and 20hp carb version from 1983 to 2008. Each one was sold and traded up to current 25hp EFI Merc

When I ran the motor all the fuel was stabilized ALL OF THE TIME. I used Stabil alcohol version. SO no mater when you stopped using it for the season ( July or November) , the motor was ALWAYS STABILIZED INSIDE

I left the stabilized fuel in the motor. No dry and never had carb problem

Take the the O/B cowl off and use silicon based spray and cover the entire power head with it. NOT WD-40 b/c it leaves no coating. Silicon does. Cover the entire motor with it. I mean paint it with Silicone spray.

And of course run the motor before that with the hose connected earmuffs to flush it for about 10 minutes. Gets rid of salt in it.

Also take a look at the sacrificial zincs on the cavitation plate. Replace ( cheap) if noticeably shrunk.

Some people suggest taking off the prop and grease the spline with suitable waterproof grease. Put prop back on and secure. I never did.

Lastly grease up any fittings near the connection to the O/B pivot axle attached to transom bracket.

Check if pull rope is appreciably worn away.

Change spark plugs every couple of years too.

Store motor vertically . MY PREFERENCE.

Hope that helps?