I met a kind 75-year-old gentleman at the lake who has a '76 (or '72?) Tahiti jet boat that he couldn't get running. I offered to help and in a few minutes we did get it running, and I followed him in my boat in case it quit. It got slower and slower until it stopped and I towed him back.  He claimed it had the wrong ignition switch (he just changed) and he was told by his mechanic that it drained the battery.  Now the boat will not hit a lick even with using starting fluid.  I did see a spark on the plug. I could see that the accelerator pump was pumping fuel into the carberator, but just a drip instead of a spray. It has a Hardin Marine motor with a 4 barrel Holly carb and a Berkley jet drive.  The boat has not been in the water for 13 years (other than when I took him out). I'm pretty good with engines and understand about fuel, air, and ignition.
Baffled about why I cant get it started with starting fluid. Could it be timing? Old gas? What else should I check?