150ETXD Crankcase stuck

[yamaha808]

Aloha All
Got a friend whose trying to remove a crankcase but all six long bolts have broke at the heads because of corrosion. The bolts seem fused in the upper casing and will refuse to let the crankcase go. He's tried heat, impact tools and penetrating oil. All have failed. Does anyone have other suggestions or technique on removing the crankcase?

Mahalo

[boats.net]

I have had to drill through the housing and cut bolts into with drill. This method is risky if you have never done it, you dont want to drill in wrong place and it has to be drilled where the hole in housing can be repaired after powerhead is removed.

[jb123]

you mean the powerhead from its seat in the exhaust base gasket? if so,yep, have to drill down from base gasket maybe 3/4" to an inch ON each bolt and THRU it, then lube heavily and lift with cherrypicker etc, then beat down/out the sheared studs. Thats a good lesson to use never seize non-sparingly.