Washed grease and grime off crankcase...BAD news...crack/break in neck of casting
around uppper bearings...scrap. Pressed crankshaft out without bothering to
remove rod caps to salvage brass reed block...that finished breaking crankcase
as rods even broken ones will not clear. My collection of brass reed blocks
increases by one...each represents a powerhead problem...usually a bad crankshaft
For some reason I have no extra crankcases and I have only broken 2.

Not much in way of salvage from this powerhead despite high hopes.
Another learning experience.

The project overall will not suffer but for time and effort expended on power head cylinder a zero. Sometimes no matter how well you play the game you still
lose.

I have a Mercury KF7 crankcase in oven at 500 degrees. Despite prior washing
resdue oil stink. Made up quick batch of muffins to cover up using kitchen
stove for outboard work. The eagle eye and nose are due back shortly. I hoped
heat would make bearing drop out...no such luck.
Louis

Tried to clean up cylinders from stuck powerhead with hone...top of cylinder shined up but hone could not break thru corrosion at lower end of cylinders. No great surprise. Sprayed pistons with PB Blaster rings still stuck. No great loss there either.

After a few days of lawn and leaf duty I got in an hour or so of basement
shop time. Honed the cylinders of spare powerhead...they cleaned up nicely.
The clamp assembly had a weld repair and the screws were rusted and one
was bent. An excellent clamp casting available lacking screws. Used Dremel tool
and abrasive disc to cut slots in aluminum then used hammer and chisel to
split out an opening to work the screws out. Some careful work with press
may make screw close enough to straight to work. Discs will be removed and
reinstlled using the Mercury Service Tool for that job. There are several
work around techniques if that does not work as advertised.

Although the spare powerhead appears good to go it will be taken apart to
check bearings, seals, crankshaft and reeds. No point in finding out later
that it should have been done while the doing was easy. Hopefully no
unexpected bad news.

Louis

The bearing stuck in KF7 crankcase came out after making a close fitting plug
on lathe to catch the very narrow edge of bearing....into the press and
cautiously pump up pressure...a little bit beyond what I thought was
wise...BANG!!! Both bearing and plug came out leaving a corroded spot where
bearing had been. I do not know if crankcase is reusable but experience
was instructive.