How do I crack the powerhead case?

[Faerbairn]

I have a 1992 Force 120hp Outboard

I have the engine tore down with the head off, the carbs off, the lower cowl off, and all of the large and small bolts holding the carb side of the power head case. Also, I have the flywheel and electrical under it off. I have tried hitting the case with a mallet, but it just doesn't seem to want to budge. Are there bolts somewhere else I have missed?

Thanks for your help.

 

[jerryjerry05]

Re: How do I crack the powerhead case?

Bolts inside the housing behind the reed valves and on top under the trigger and in a couple of more places.
The cases are glued and screwed so a mallet will just tire your arm.J

 

[Frank Acampora]

Re: How do I crack the powerhead case?

After you are certain ALL the screws and bolts are removed and the bearing retainer on the top of the block is removed, THEN using a punch, drive out the two tapered pins; one high and the other low on the opposite side. Then use the two pry points between the case halves with a VERY large screwdriver or small prybar; one high on one side and one low on the other side.

 

[Faerbairn]

Re: How do I crack the powerhead case?

I have removed all bolts and driven out the guide pins with a punch. I have the face of the case apart, but it seems to be together tight at the bottom. Are there any bolts under the case holding that part on? Do I need to remove the power head from the bottom part?

Thank you for your help.

 

[Frank Acampora]

Re: How do I crack the powerhead case?

Did you remove the two 1/4 X 20 fillister head screws directly below the bottom two 9/16 head bolts? These squeeze the seal in the bottom of the case and will hold the halves together.

Did you remember the 1/4 X20 3/8 head bolt that goes in behind the starter mount? It is the only one that screws in from the other side of the case.

 

[Faerbairn]

Re: How do I crack the powerhead case?

Thank you for your reply.

Yes, I removed the allen head screws under the bottom 9/16" bolts. I removed the alignment pins.

I have the top half of the crank case pulling apart about 1/2", but the bottom will not budge.

Still,the bottom is rock solid in place. Is it glued in place? Should I use a heat gun on it? Any ideas would be very helpful!!

Thanks...

 

[Frank Acampora]

Re: How do I crack the powerhead case?

It's not glued, per-se. the sealer or spaghetti tubing may have hardened and may be sticking or you may have a really tight bearing.

I really hate to say this, but try wedging something flat between the halves as far down as you can and smack the top of the case with a rubber mallet.

Before you take this drastic measure, you know the old adage: Measure twice, cut once! Double and triple check that ALL bolts are out.

 

[Faerbairn]

Re: How do I crack the powerhead case?

Thank you for your help. I truly appreciate it!

I have tried everything suggested and it is just not coming apart. Where the case halves meet is apart, but there is a gasket of some sort at the bottom of the front case, and that seems to be where it is stuck together.

What can I do?

I can pull apart the top by hand, I have banged all over the front case with a rubber mallet.

 

[Frank Acampora]

Re: How do I crack the powerhead case?

You know: It has occurred to me that sometimes the front half will stick on the crankshaft cheeks if it is removed at too sharp an angle. Have you tried prying evenly on the bottom half and the top half of the case and lifting straight up?

As I recollect, even as late as 1997 there was no specific gasket at the bottom of the case. The only thing there ever was was spaghetti tubing between the crankcase halves and that is just not strong enough to stop you from separating them.

I have seen where the center bearings were so tight in the case that it was necessary to pry them apart, bending the spring steel clip that holds the halves together. This may also be what you are experiencing, in which case, you have no choice but to force it.

 

[Faerbairn]

Re: How do I crack the powerhead case?

Perhaps I am using the wrong terminology. I am trying to pull apart what i understand to be the crankcase. It sits on top of a case that the lower unit bolts up into. There appears to be a plate sitting between the crankcase and the middle case. The crankcase definitely looks like it is on a gasket and I am wondering if there are bolts under attaching the plate to the crankcase?

 

[Frank Acampora]

Re: How do I crack the powerhead case?

Ah-Ha! Now I understand! I thought your block was already separated from the match plate between it and the midleg. Below the block is a match plate to which the exhaust down tube attaches. Passing through this plate are four studs: two in the front half of the crankcase and two in the rear half. All four are held by nuts under the match plate.

You must remove the four 9/16 nuts and tap off the match plate before you can separate the crankcase halves. It may come off easy or may be difficult. The gasket between the crankcase and the match plate will most likely be destroyed since it has a factory applied glue.