Re: 1989 force 85hp
This engine has a plate covering the water jacket on the head. To reseal it you must remove the head bolts and the three bolts next to the spark plugs. Separate the head and cover, clean off any corrosion, lap them together with a little lapping compound ot abrasive sink cleanser. Clean again and coat the mating surfaces with a light layer of silicone sealer or red Permatex and re-assemble.
Be careful with the bolts next to the spark plugs---they tend to snap off.