1978 Johnson 70hp head removal - what am I missing?

[ronwj]

I have water coming out of the bottom cylinder. I plan to take the head off and replace the head gasket.

Question is, I have removed the 18 bolts holding the head in place. As far as I know those are the only bolts holding the head on. But the head will not come off even with a moderate amount of tapping with a piece of wood or a brass drift.

I hesitate to go harder at it because cast materials have been know to crack.

Question, is 18 bolts all of the fasteners I need to remove? IE is there something hidden there?
If I have all the bolts, what do you suggest I use to remove the head without damaging it? It is on there solid.

Thanks,

 

[Bosunsmate]

Re: 1978 Johnson 70hp head removal - what am I missing?

put some bolts back in loosley and run the engine using compression to try and force it open

 

[Chinewalker]

Re: 1978 Johnson 70hp head removal - what am I missing?

18 bolts it is. Might have to use a bit more brute force. See if there's anywhere you can wedge against to GENTLY pry against the head, taking care not to booger up the head surface. I say gently, because it is possible to warp the head if you pry with significant gusto.

Not sure I'd do the starting method to pop the head. Good way to start a fire as you'll have gas and spark in the area...

 

[ronwj]

Re: 1978 Johnson 70hp head removal - what am I missing?

It came off!!!! After leaving it and coming in for lunch and asking for advise from you folks, I went back out to the shop to look at it some more. Seems it loosened up significantly just sitting there for a couple of hours, it almost fell off.

The bad news is the water seems to be coming in through the exhaust port. I'll need to review posts to see what I need to do to fix this.

Thanks for your suggestions and confirmation re 18 bolts.

 

[boobie]

Re: 1978 Johnson 70hp head removal - what am I missing?

Most likely the exhaust cover gaskets or plates. Those motors had that problem.

 

[Bosunsmate]

Re: 1978 Johnson 70hp head removal - what am I missing?

Thats not a bad result the worst would be if it was a cylinder or head crack. Take care getting the bolts out, heat them up tap them a bit etc. Check the plate and surfaces arent warped by using a straight edge, sand down on a plane of glass if needed