1997 Mercury 2 stroke twins poppet valves

[Redman22222]

Overheating at high speed on the cxl, looking to change the thermostats and poppet valves on both engines while I'm at it. Ordered Parts and went to take a look at what would need done. Found the thermostats but can't seem to find the poppet valves location. Looked at my manual but still can't find the locations? Rebuilt the water pumps and pretty sure that's not he issue since I had the same overheating problem prior to the rebuilds. Can someone tell me where the poppet valves are? I must be missing something, should be easy to find?

 

[Redman22222]

Theses are Mercury 200 hp, carb twin engines, still haven't found the poppet valve location.

 

[Texasmark]

Got a hose coming off the power head, probably at the top going down below the block to the mid section (not the pee tube or pee tube could be plumbed off it)? IF so check out the lower end of the hose for attach ment to the PO valve. Merc Serv Man for a smaller engine says at about 2500 rpms the PO takes over from the stats. High speed alarms are PO, water pump, or debris.