If you think the injectors may have had water in them, you might want to consider sending all your injectors to the Injector Man in Naples, Fl. for a spray pattern check and possible cleaning.
http://www.etecownersgroup.com/post/...ervice-6054423 At only $44 ea., it might be cheap insurance on a motor of that vintage, even if the dealer says they're ok.
I've spoken to owner Dale and he seems very knowledgeable. Said he's always been a Merc/Yamaha fan, but he was so impressed with the engineering and spray pattern of the E-TEC injectors that when his old Merc crapped out on his own boat, he repowered it with a new 175 E-TEC!
BTW, the injectors MUST be installed in the same cylinder they came out of, because each injector has unique flow coefficients that are loaded into in the EMM. New injectors come with a bar code the dealer can scan to obtain the coefficients to be loaded into the Engine Management Module.