Suzuki dt25c cooling problem

[Coopaloop323]

Ok I am at a loss here. Just bought this boat with a 1990(or so) DT25c 2 stroke oil injected engine on it. Pumped water for the short bit I looked at it. When I ran it when I got home doesn’t pump water. Pulled the lower unit took the impeller out. It looked a little chewed up but not bad. I replaced it spit water for about 2 minutes then stopped. Been trying to clean the passage thinking it was clogged no progress. Spent 3 hours trying to flush from the tell tail hole and backwards through the pick up tube with the lower unit off. I can get water to pump through with a hose directly through the water pickup tube but I cannot get it to pee with the lower unit on. From what ive read if there is a bad thermostat it will still pump water but I don’t know. Any help would be much appreciated.

 

[Coopaloop323]

I also want to add I have ran it with a bucket and a hose attachment but getting no response either way