while draining the lower unit gear oil the drain plug (that is not to be removed) was removed. this in in a 1988 Force 85HP Outboard motor. There is a fill & vent plug that get removed & this drain plug on the lower unit. I had a megnetic screwdriver that pulled the plug out by accident and now i can't get it back in. it appears that something spring loaded has prevented the the drain plug from going back in... Does any know how to fix this? does the lower unit have to be taken apart? and if so can someone w/ average mech. knowledge of cars tear into this w/out causing bigger problems?