I was recently told that my motors might run better bye changing the thermostat from 140 to 170, supposibly merc has found more power there anyone ever hear of this motors are 1994 502 efi's

You should have a 160 degree stat if you have EFI's. If you don't your engine will stay in start up mode and run rich all day long.

Runs 140-150 160 after a run then back to 150 or so

1998 502's, mine have 160s adn the guage shows 180 all the time after warmed up

http://www.offshoreonly.com/forums/g...t-502-mpi.html

1994 502EFI's use 160* Tstats from teh factory. Somebody may have put 140's in yours. It should run 160-180* on the gauge.