Tips on removing powerhead

[dsujen]

I have a johnson mod.# 70EL78c that was used exclusively in salt water. I have to take off the power head to fix water leaking into the engine compartment around the base of the powerhead. I don't have the shop manual. Any tips like shifter position, and ways to remove stubborn bolts ect. would be appreciated.

 

[F_R]

Re: Tips on removing powerhead

Shifter position won't matter, but you will be disconnecting it anyway. One thing you can count on will be some stuck bolts. Intense heat as from an acetylene torch, and lots of cuss words will help. Even the pros have been know to utter a few words, and it is just a normal day's work for them.

Hint: Avoid breaking the bolts off. Use that torch heat. And if you have to destroy something, at least try to do it to the least expensive part.

 

[Bosunsmate]

Re: Tips on removing powerhead

Living here by the salty sea those bolts are the worst part of rebuilding any motor by far. But once its done its good to know it will be easy any next time next the powerhead needs removal. I replace the steel bolts with stainless ones and i coat them in antiseize.

As above, heat is the best thing you can use. Keep the motor vertical and heat the head of the bolt until they get red hot. The exhaust will blow smoke from unburnt oil in there. I remove the washers and when the bolts hot i give them a short rap with a hammer to help break up the oxidation seizing it in there. When it starts moving, keep alternating between tightening and loosening as often you will get movement but if you dont alternate the threads will lock up with gunk and then off goes the bolt head.

Some people heat the outer casing but be careful as that is aluminium.
On really bad ones ive had to drill the bolt sideways through this casing near the top of that bottom plate. So long as the hole isnt too close to the top plate you can refill the hole later with high grade epoxy and it wont matter a thing. The bolt thus sheared will have the top end come out of it with the powerhead and you will be amazed how easy they undo. Its the oxidation/gavanic corrosion, whatever its called between the bolt and the housing which causes the problem.
After doing many thats the only tips i can offer.
Just realise before you start that you may need to spend some time on it then you should get there without too much damage