I just rebuilt my carburator and the engine runs great but it is getting to hot. I checked the impeller and it looks ok though I found water in the gearcase and it looks like the seal under the impeller is shot.Could this be the cause of water not making it up the tube to the engine? It seems to me that there would still be enough force even with a small leak to get some water up the tube. Regardless I need to rebuild the lower end but not sure if this will solve the overheating. Also noticed some scoreing on the driveshaft where it rubbed with the shot seal. Do I need to replace the driveshaft?