120as ... change filter every 10 years ... where are you getting fuel. here in Naples they claim they have a bug killer in it.
#505 never had tank cleaned ... but off shore a lot of sloshing around. last year did find "thick goo mud" in bottom of plastic racor bowl ... keeping an eye out for it now.
parts for that motor should still be available easy. I had the ring holding the filter on ... crack. and the high pressure line spring a leak ... since 1984.
filter link 
