hi, i need a bit oh help. i have an older mercury 700 motor (1978 70hp 3 cyl)i use the boat for the wife and kids mostly. i changed my impeller and am having problems removing the old drive shaft seals. they are stuck in the upper section of the drive shaft housing. i am attempting to remove the housing to examane the problem and change the corrisponding gasket, but cannot remove the upper motor mounts. to my understanding four bolts hold the upper mounts in the housing and one through bolt, on each side, throught the stearing yoke ties it all together, problem is the yoke bolts simply turn with out backing out. i assume there is a corrisponding nut in the housing that is turning freely. do i grind off the head and replace or is there a trick of the trade? please help. my clymers manual is very vague on this area.<br />unrelated, but i noticed that the plug in my #2 plug is more fouled (wet) than plug 1 or 3 any tips on how to fix or what the cause could be?all compressions are with in range, actually almost exact.<br /><br />thanks,<br /><br />david in new orleans