older Disk Rotor .67 Marine problems

[rigged]

ok, so after inspecting everything, ive come to find that the slot the crankpin connects into on the disk has gotten opened up letting the allowing 20 thousandths or so slop. I realize this is a bad thing, so now im looking at my options.

My first question... can i switch to drum rotor using PT#21-6791? If so, are the cranks the same or will i need to replace the crank as well?

My second question... as an alternative would it be better to just try to find somebody that can machine me a few disks?

Thanks for the help.

[MECOA]

.020 won't make it run much different.

The drum valve will fit but the case has to be modified as the fuel/air charge enters the engine on an upward angle into the cylinder. The crankcase must have a clearence milled (or dremeled) into so the fuel/air charge isn't obstructed.

You can turn the entire back plate and rotor upside down and run the crank pin in the other slot. (if the rotor disk has 2 slots.