Yamaha lower unit removal problem

#1 02-15-2005, 03:59 PM

All my previous boats have had straight inboards, so working on outboard engines is new to me.
Tried to remove the lower unit on my '91 150 yamaha last weekend to rebuild the water pump, but couldn't get some of the mounting bolts out. Of the seven bolts that attach the lower unit,
I was only able to remove two Two others are turning so hard, that I'm afraid that their galled in the aluminum. Two others I can't move at all, and the one in the zinc anode is stripped out. It turns, but won't come out. I don't think I can get penetrating oil into those vertical blind holes. I'm tempted to try to heat these bolts while trying to remove them.
I'm hoping some of you guys may have experienced this problem and found a successfull
way to deal with it. Any suggestions will be appreciated. ???

chumbucket · #2 02-15-2005, 04:10 PM

Break out the torch and heat them up. You're gonna need a paint job afterwards, but it's the only way you'll get them out. Use anti-seize for the install, and don't skimp. Get the marine grade stuff. ;)

#3 02-27-2005, 07:33 PM

Finally got the bolts out, except for one that broke off down deep. I'll try to deal with that one after I get the gear case off. Now I can't get the gear case off; it won't budge. After spraying lots of WD-40 and beating on it pretty good, it still won't loosen up. Any ideas on how to proceed?