I have a 1985 Glastron X19 that we bought this summer and we are having what we believe to be fuel related issues. The first time we took it out; after a few hours of it running great....we stopped for a swim and after it sat for about 30 minutes it would not start. It was as if the carb was not getting any fuel. The gas gauge showed 1/2 tank but we were not sure if it actually worked. We went and got gas and put 5 gallons in it we were able to get it started. The 2nd time we took it out on a full tank it ran great and then again the same thing. We knew we were not out of gas but possibly about 1/2 full again. I had a mechanic look at it and he adjusted the timing, carb, and said the accelerator pump was bad in the carb. So thinking we are good now; here we go the 3rd time....rode a few hours and it ran great....stopped for a swim and once again would not start and not getting gas to the carb. A friend with us siphoned up enough to get it started so we could get back to the ramp. Again, we had 1/2 a tank of gas. I feel as though the gas gauge is actually correct based on the amount we put in to fill it back up. Told a friend about it and he looked at it and discovered the fuel hose between the carb and manual fuel pump was missing a clamp and was sucking air as it was actually a bit loose too. We were able to start it up with the muffs on with the 1/2 tank so thought we might be okay. So we head out for trip #4 and fill it up with gas as the marina is closed and wanted to make sure we had enough just in case the fuel gauge was wrong. Started right up and ran really well for about 3 hours. Wanted to let it sit at the dock before loading for a little while to see if it would start okay. It started up but didn't seem to be getting enough fuel as I had to restart several times between the dock and ramp and then would not start at all. Again not getting fuel and again between 1/2 and 3/4 tank. Not sure if the 1/2 tank is coinidence or not but that seems to be the case everytime or if the riding a few hours and then sitting is it. When we started it after he put the clamp on there had been 2 weeks in between starts. Any suggestions?