Looking at 2 boats,1 has a 2003 115 hp 4 stroke & 1 has a 2005 115 4 stroke both yamahas. how should have the owner broke in the 2003? it has 160 hr. Can one use Dello 15-40 in these? The boat will live in Mexico so no winterizing but summerizing will be needed{ temp gets to 110 and humidity...