RIP Lower Unit! 1987 Evinrude 175 Crossflow Fire Up

We did a lot of work to the boat over the summer including changing the lower unit oil. Wanted to do a test fire to make sure it's ready for the water. I don't normally shift on the trailer, but I wanted to see what it was like with the new oil. Like a proper idiot I didn't wait long enough for the prop to spin down between forward and reverse. Excellent grind action!
Can't be much worse than what the PO did. Oil came out like molasses because it was half metal powder! LOL! At least it has new oil in it now.
Idle is high for several reasons. Motor can't get fully level while sitting on the trailer, so the carb bowls aren't quite happy. The linkages are super crusty and full of friction, so it never fully returns to base idle. It's out of the water, which is how it's supposed to be set, because being in the water and in gear lowers the idle significantly. I have replaced the entire fuel system including fully rebuilding the carbs, plus it is linked and synced pretty well, so it actually runs great on the lake.
Wasn't getting enough water flow from the hose, so it was getting a little warm kinda fast compared to being in the lake. It was inching towards 150 °F.
Above all else, I barely know what I am doing and still learning, so I realize I look dumb! Just trying to give details before I get a lot of angry comments below.
Boat is a 1976 Tahiti 18'. Current record is 55 mph. Goal is 60. Lots of room to raise motor and play with props.
Yes I realize the motor cover says Johnson, but it's an Evinrude E175TLCUA.

[@juanclemons1492]

your idle is way to high when you shift gears.that will mess them up

[@mjodr]

This thing is on it's last leg. It won't idle low enough to meet the factory manual spec due to many issues including one cylinder with low compression that is nearly dead. So yeah, idle is too high. It's not *too* bad once it's in the water and there's backpressure on the exhaust, but still sounds like crap when I shift, lol. Whatever, it's a low budget setup.

[@Craftsmansteve]

Maybe adjust your carb down to lower the idle to compensate all your problems? Not sure but might work