johnson 150, won't crank was running fine

I have a2000 johnson 150, its been a little tempermental after replaceing lower unit. It would turn overheat light on and start to sputter. I would shut it off wait 5 minutes and start it back up it would be ok if I kept rpm's down. So I was easy on it until I got home, I found that water pump sleeve(rubber sleeve between middle and lower) was crushed and restricting water flow. put it back together, ran it on the water it was great for about15 minutes at wot ,good pee stream no lights, as I was coming back it started to stumble, I could nurse it along at about 1200 rpm, got it back. let it sit for about 20 minutes. re=started it it ran for 30 seconds and died. now won't crank, battery is strong, I think power head locked up. as I can't turn prop by hand in gear, I used to be able to. prop spins freely in neutral. I tried tapping on starter,no change. my vro did take dump about 25 hours ago, it ran 2 minutes at a time low rpm, getting back to dock, I could squeeze bulb and make it run. but I have put 25 hours on it since then, ran great until I broke a blade on prop and damaged lower unit in Canada. Anything I should try before I go after a new power head?