I just got a 94 SPX to mess around with. When i first got it on the water it ran fine the first day, second day it started acting goofy, gave a beep like it was over heating, pulled the sensor (cleaned and tested) put it back in with new plugs and gas. It ran great for about 15 mins then would just completely quit. After that i could get it to run by playing with the choke. It randomly decided to run like a raped ape for about 50 yards then bogs out. Maybe a card rebuild or am ecm issue?