1st start up, no water coming out.

[winterhawk]

This is a late model A4 in a Yankee 30. They have a midship engine with a stand pipe in the head.

I fired the engine up today for the first time in 2 years. I have new exhaust hose, it's a long run 14 feet of hose, plus the stand pipe. I assumed I'd have to wait a little bit for the stand pipe to fill up. But even after running the engine for 30-60 seconds 3 times no water came out of the exhaust.

The boat is on the hard so I had a couple 5 gallon buckets of water in the boat. At first the water went down a bit, and a finger over the end of the hose revied a little bit of suction. Not a lot. From time to time the suction would increase but then went limp again. I shut her down, made a call and a friend says check the impeller. I pulled it and it looks OK, but I'll replace. All the hoses in the cooling system are new. I pulled the T stat and visually inspected. Looks ok. reinstalled.

Where should I start?
should I start with some sort of flush? Maybe start to isolate where a blockage may be by unhooking a hose here and there and verify flow?