Evinrude 90HP Powerhead removal?

[Fisherevins]

Hello, Evins here and I am writing about my evinrude 90HP motor which is stubborn to take off. I've read numerous posts and seen numerous videos but I can't seem to remove the powerhead.

I've removed the lower unit and the 6 bolts and 4 nuts holding the head in, chained the motor to the cherry picker, used rust penetrator and some heat, bashing it with rubber mallets and hammering no thread bolts up one of the 6 bolts.

I have broke one of the studs off the 6 bolts and tried drilling the remaining out but with no luck and has had it weighing off the cherry picker for about 2 days with bashing but it still won't come off. Some ideas I have is using a putty knife to hammer in the head itself but am afraid of screwing it up.

The main reason for removal is I'm losing compression and suspect the piston ring is destroyed as the pistons show some metal bashing and I'm going to replace all of them.

Thanks.

 

[boobie]

Model # ????

 

[Fisherevins]

E90TLCNB

 

[boobie]

Any bolts or nuts on the back of the power head holding it down ??

 

[Fisherevins]

I've removed them and there is slight movement, the slightest upon prying it with a pry bar.

 

[racerone]

On your bench you should have 6 long bolts and 2 short bolts and 4 nuts.--You should also have 2 bolts 1/4" from cowling to the block.

 

[Fisherevins]

The cowling has 3 latches that you can undo but other than that I have removed all the bolts and nuts

 

[racerone]

No,No------The lower cowling is attached to the block with 2 bolts. They are 1/4"

 

[Fisherevins]

Ah yes sorry, they're removed

 

[Fisherevins]

Currently so far I have been bashing it with a rubber mallet and used rust penetrator for over the past 3 hours in interval timing of 30mins

 

[racerone]

Put the 4 nuts back on ( protect threads ) and use a hefty prybar on them ??

 

[Fisherevins]

Good idea will try that tomorrow! It's being left on a cherry picker with pressure hoping it would break loose because the 3 out of 4 of those nut studs are stuck.

 

[interalian]

+1 on Racer's prybar tip.

You say you broke one of the 6 (long) bolts. How much bolt is left in the hole? Aside from the adapter to block gasket, there shouldn't be anything holding it on. Can you put a punch in the hole with the broken bolt and strike it while keeping tension with the lift?

 

[Fisherevins]

I have tried that with another bolt but will try a punch when I have time to get one. Will see how it goes with the prying and bolt striking. Thanks for quick replies!

 

[Faztbullet]

Sounds like a brackish water motor..have you removed lower unit as driveshaft can seize into crankshaft?

 

[racerone]

Post # 1 says lower unit is off.

 

[interalian]

Yup. Time to get medieval on it.

 

[Fisherevins]

With roughly a days pressure on a cherry picker the loop broke off so I chained around the motor but still no luck as of now will still try to bash on it until something breaks or I get a new motor.

 

[daselbee]

There is a trick that hasn't been mentioned.

I am not sure of exactly where it is stuck, but the studs that go thru from the block to the exhaust adapter are notorious for getting locked in place by the generation / growth of aluminum oxide between the adapter and the bolt itself. That is the white powdery stuff you are seeing. If you have 4 stuck like that, no amount of beating will break it free.

The trick is to visually locate the line that the stud would follow when going down thru the exhaust adapter. Drill into the side of the exhaust adapter ON THAT LINE, and as near to the bottom of the block as you can. That would be the bottom of the block, and the top of the adapter....where the two parts meet.
And remember you are drilling the exhaust adapter, and drilling a hole that is coming in from the side. Drill on that vertical line, trying to hit the side of the stuck bolt right in the middle of the width of the bolt. Good hand / eye co-ordination, if you get my meaning.

Use a small drill. You will be going thru aluminum first, then you will hit the side of the stuck bolt, which is steel.
The idea is to drill thru that stuck bolt/stud with a small drill, increase the drill size until you actually drill thru the stud, thereby "cutting it" in two pieces.
Usually this is at about the 1/4 inch drill size, or maybe 5/16 inch drill.

When you successfully cut all four stuck bolts by drilling thru them from the side, the block will come off.

Now, you say, what about the holes? No problem. Install new studs after you remove the stuck pieces with a big hammer and punch (or a stick of dynamite), do your powerhead work, replace the powerhead, torque it down, and fill the holes with a dab of silicone or something equivalent. No harm done.

The only problem with this is that sometimes you cannot physically get to the correct spot to drill......
You will have to determine if this will work for you.

 

[Fisherevins]

Yes the exhaust bolts that stuck out was so corroded that it almost welded itself to the adapter but after smashing it so much with a rubber mallet it was persuaded a bit so I used a hefty pry bar and pryed the block area and slightly damaged it but it's fine. Then used the cherry picker and to my surprise it dropped and scared me. Haha.

Thanks for all the help guys. Best luck to you fellows.