Bike won't run

Just got a project 1977 kz650 c. I replaced the battery, the spark plugs, and I've cleaned out the carbs but the bike will only run for a few seconds if I spray starter fluid into the carbs.

Any advice?

The old saying is...for an engine to run, it needs 3 things; fuel, spark and air. You have all 3 when using starter fluid as your fuel source. The carb should provide the fuel, but it's obviously not. Since you said you cleaned the carbs, are your getting gas from the tank? Are the float bowls full? How did you clean the jets? It's a tiny hole that's easily clogged and hard to clean. For the price, it may be worth buying a rebuild kit with new jets. The bottom line is the problem is in your fuel delivery system somewhere.

I used carb cleaner and compressed air to clean out the carbs and when I open up the drain plug gas flows out. I suppose I should measure the float levels?