I have a 120hp johnson 1990 and this season the boat died twice as if it was out of fuel but it would start right back up, also the warning horn has sounded a couple of times at fast speed but would stop at loow idle. I noticed when starting up to winterize that the in line fuel filter was empty and after pumping ball it only filled half way leaving an air pocket in the filter. Is this normal or could the checkvalve in the primer ball be defective?