Agreed-----The 60 degree motors with carburetors are very good.-----Even better if you can do your own work.----Finding a shop for work on older motors can be an issue in some areas.
A 1990 is shown to have a temperature switch.----It is likely the overheat warning and needs to be investigated !----Sad that folks do not replace impeller every 5 years or so.
Check valve clearance.------Check compression ( throttle open ) ----The powerpack ( big $$$ ) has an optical sensor.-----Does spark jump a gap of 3/8" on both leads ?-----Perhaps oil pressure switch is acting up ?
The fuel does NOT go through the crankcase on these FICHT motors !!-----Crankshaft and bearings would not see any oil.------Motor would quickly come to a " dynamic halt " and be ruined.----