howdy, i puchased an 1969 rennell 18ft. with an 1967 evinrude 80hp model# 80753 for $400.00. anyway i just got the motor running and i noticed oily substance in the holding tank. smells like gas. could it be unburnt fuel? any suggestions on how to fix this? also can i use those earmuff things (for the water) instead of a water tank? and were do i hook it up at?<br /> thanks for your time guys.