Breather Tube Smoke on Startup and Low Power

[Retired2021]

I have a 1999 Yamaha G16A gasser. Lately I noticed low power and exhaust smell. I removed the air cleaner and noticed smoke out of crankcase breather tube upon initial startup. Also the exhaust sounds different, more of a muffled pop pop if you know what I mean. New plug, and fuel filter installed. Any suggestions greatly appreciated.

 

[Zman]

Any smoke out of the muffler?

 

[Retired2021]

Not noticeably

 

[Zman]

Valve lash needs adjusted.
Muffler getting plugged.
Low compression.

 

[Retired2021]

Is it possible that the muffler is clogged or somehow compromised?