I just bought a 1997 FourWinns horizon 200. It was not started for 6 1/2 years. I pulled gas tank, changed water/fuel seperater, new plugs, cleaned carb, and put new water pump impeller on it. It will not stay running???? its getting gas, but will only stay running with added help through the carb. Almost like not getting enough gas. Has any one else had this problem? can any one help me trouble shoot?