Advice to remove the damage keyway

[Force 120]

I got a low compression (50 psi) on both cylinders of 1988 15HP Johnson.
It turn out the keyway got damaged. I have tried to get it out different way but I could not.
At first I thought the cylinder got scored but upon removing the head the cylinder wall still look good. So I removed the flywheel and found the keyway got sheared. But base on your experience, which way is the safe way to remove it. I have sprayed the PB blaster overnight and try again. I think a bout drilling it out but I don't want to damage the crank shaft.
So I seek the advice from the forum.

 

[Bob_VT]

Not too hard to do.

Use a sharp punch (start with a brass punch then move onto steel if needed) and work on the broken key. They are normally softer then the shaft bu just take your time an a few srong raps should drive it out..... IF you see any movement then with a small chiesal get under it.

Use a decent tool set........ not saying that a cheaper one will not work but chiesal quality helps.

 

[tphoyt]

Agreed work the ends one side then the other until it starts to pop up on one end. It’s a half moon in the crank so it will work it self out in theory.
Best

 

[Force 120]

I have tried many method and did not work. I think about the last resource is to drill the keyway out but

 

[racerone]

???____Work like a dentist.----Get a dremel tool with a thin cutoff wheel.----Split the remains of the key along the length.---It might fall out.----Gentler on bearings that way too !