most didn't get taken in for the cooling mods. is the telltale nipple at the top of the block on the exhaust? what temperature are you getting at #1 cylinder? Air would get trapped in them, and cause hotspots hence the service bulletin. do a search for the bulletin, #2276. the water pump upgrade included a grommet for the water hose as well.
If you are testing it in a tank/drum,the water pump needs to be below the waterline to purge the air out and for it to prime.
If you are using muffs,it won't prime properly.
i wouldn't worry about anything unless it's overheating on the boat in water, but is the telltale elbow at the bottom or top? try sticking a paperclip in the cooling nipple... sometimes gets clogged. you can blow into it with compressed air if it seems clogged as well.
the 90 degree elbow that the cooling hose goes into in the block. bottom or top?
So just monitor the motor and you want to avoid surfacing the lower unit if you can help it without doing the cooling mod. if you get an IR temp gun, the temp at idle should be 125-155 degrees. I took a pic of the bulletin for you and its below. It's an easy and satisfying sunday afternoon job. don't worry too much about getting metal shavings in the exhaust area, but i recommend a vaccum cleaner and going slowly to suck up as many chips as you can, and of course greasing the drill bit as instructed.
So just monitor the motor and you want to avoid surfacing the lower unit if you can help it without doing the cooling mod. if you get an IR temp gun, the temp at idle should be 125-155 degrees. I took a pic of the bulletin for you and its below. It's an easy and satisfying sunday afternoon job. don't worry too much about getting metal shavings in the exhaust area, but i recommend a vaccum cleaner and going slowly to suck up as many chips as you can, and of course greasing the drill bit as instructed.