cant seperate powerhead from driveshaft housing...help

[turbocorrado]

motor is a 1985 mercury straight 6 115hp 2 stroke.
my wifes grandfather blew the motor and im trying to pull the powerhead off the boat. everything is disconnected and ready to come off. got the engine hoist on it and its lifting the whole damn boat lol. its all seized up, the repair manual i have says use heat and an air hammer on it. which i dont mind doing, except my air hammer and torch are at work and i would really like to have this thing separated today.

ive got it slightly hoisted right now, hoping that the pressure may separate it while its sits there. are there any other methods i can try, or should i just wait untill i have my air hammer here

 

[1979checkmate]

Re: cant seperate powerhead from driveshaft housing...help

make sure you have all the bolts out - there's two at the front that are easy to miss. I just did this a few weeks ago.. i ended up just putting some pressure on the engine hoist and taking some weight off the trailer.. then i got in the boat and jumped around a while - it broke free eventually. May not be the most graceful way to do it though! My motor has been in only fresh water it's entire life though.

 

[turbocorrado]

Re: cant seperate powerhead from driveshaft housing...help

make sure you have all the bolts out - there's two at the front that are easy to miss. I just did this a few weeks ago.. i ended up just putting some pressure on the engine hoist and taking some weight off the trailer.. then i got in the boat and jumped around a while - it broke free eventually. May not be the most graceful way to do it though! My motor has been in only fresh water it's entire life though.

yeah i saw the 2 up front at the last minute. its seized pretty good. all 8 nuts are off.

i have a pretty sweet mental picture of you jumping around in a boat now :lol:
if i try to jump in it, i will go through the floor. its gotten pretty soft. and the motor has spent the past 15-20 years in salt water :facepalm:

 

[racerone]

Re: cant seperate powerhead from driveshaft housing...help

Will the lower unit come off ?

 

[turbocorrado]

Re: cant seperate powerhead from driveshaft housing...help

Will the lower unit come off ?

im not sure, i havent tried to take it off yet, im pretty sure the engine is toast so im trying to take apart as little as possible and not waste to much of my time

 

[racerone]

Re: cant seperate powerhead from driveshaft housing...help

You need to determine if the powerhead is stuck to the exhaust housing ( corrosion jamming the studs ) or if it is something else.-----There is the possibility that the driveshaft spline is rusted into the crankshaft.--It could be that the powerhead is not stuck , but the driveshaft is.-------Removing a few nuts and bolts on the lower unit will help in determining what is the problem.

 

[sam am I]

Re: cant seperate powerhead from driveshaft housing...help

You need to determine if the powerhead is stuck to the exhaust housing ( corrosion jamming the studs ) or if it is something else.-----There is the possibility that the driveshaft spline is rusted into the crankshaft.--It could be that the powerhead is not stuck , but the driveshaft is.-------Removing a few nuts and bolts on the lower unit will help in determining what is the problem.

Good point racer, I also hear tale that overheating(among other things) can seize the driveshaft splines into the crank as well.

OP, you could be fighting city hall if you don't know forsure that lower unit will drop out first.