This about the GM ignition modules , I did not know they were also used for boat engines and I find it strange that they have an inbuild advancing system from standard , depending on the RPM rate without being corrected from the ecu car computer , but apperently all these 8 pins units...
I am currently having problems with these EST systems in my Chevy V8 , finally I have connected my scope on the primary of the coil and I could clearly see what is going bad ; even a new Standart LX340T iginition module was not working properly , what happenend is at idle I had erratic...