2003 mercury 150

[eggsuckindog]

The Carb motors are really tough, all of them.

[Fr. Frank]

The Carb motors are really tough, all of them.

Yes, but never, never, never take out the poppet valve and run your engine like that. The poppet valve raises the water pressure in the water jacket of the engine. Without it, portions of the block & water jacket can run "dry" and overheat and warp.

[Bigshrimpin]

http://www.biggerhammer.net/mercury/
It's like cliff notes for two stroke merc engines

I got the diagram off that site, but it's right out of a service manual.