DT-40 No Compression 1 Cylinder

[Kalvinc]

Last weekend the outboard was running great. When I started it back up after stopping, I couldn't get it to stay running in gear. I had to rev it up high and slam it into forward and eventually limped back to the ramp. Tested compression. 0 compression in the top cylinder, 100 psi in the bottom. What is the next step?

[Solarman]

I might pull the head off, in hopes that it's a blown head gasket.

Good luck, post back on what you find out.