I'm having the same problem with a Johnson 9.9. It started great on electrical start without fail after I bought it last year, ran it six times last fall, bought the manual, did all the things I was supposed to do before storing it in the barn for the winter...cleaned the tank, fogged the cylinders, burned the gas out of the carb, etc. Didn't get back to it all summer, long story, until a few weeks ago. Put in fresh gas and oil and a shot of SeaFoam, ran it in a tub here at the house, seemed to be good. Worked with electrical or pull start. Got it to the lake last week, ran it for a couple of minutes at the dock, peeing water like it's supposed to, put it in reverse and got 15 feet from the dock. Stalled. No joy. Back at the ranch today, it did the same thing for about a minute.
I have no indoor heated shop to work on it, getting too cold outside, must put it away for the winter and tackle it again in spring.
Question: In the tub, the water intake is covered with water up to the cavitation plate, but not the out-take (it was squirting fine at the lake). Did I screw up there?
From what I'm reading above, I also have a fuel supply problem. Yes, no, suggestions?
Thanks...