1998 Mercury 225 EFI Saltwater Series

[fmackjr]

I don't have any experience with outboards and have a question. I'm thinking about purchasing a boat with twin 225 EFIs. I went for a sea trial and while the engines were warming up they smoked (bad in my opinion). After five minutes the smoke stop. During the sea trial the engines ran perfect. I didn't take the rpms past 5200 because of conditions. While running 3800-4000 rpms the water temp on both engines was 140 degrees, but going back to the dock at 1,200 rpms, one engine stayed at 140 and the other dropped to 120. I was thinking a thermostat problem, any suggestions? Is the smoking went cold normal (the smoke is enough to offend others if they are on their boats)?

 

[kevinburns]

Re: 1998 Mercury 225 EFI Saltwater Series

almost any outbaord will smoke quite bit upon initial start and even at low speeds. It's just the nature of the beast. Those engine are pretty decent. I wouldn't worry too much about the temp differeneces as long as you can see water shooting out the back of the motor while under power.

 

[clanton]

Re: 1998 Mercury 225 EFI Saltwater Series

The thermostats begin to open at 140/145 degrees. Not real sure on this engine, but you can adjust the oil pump on the carb engines, if maladjusted it will smoke more.

 

[suzukidave]

Re: 1998 Mercury 225 EFI Saltwater Series

I can't tell if the symptoms you describe are trouble or not (my motor smokes like crazy when it starts). It could be an oil-mix issue. Those are good motors but even if they showed no symptoms at all I wouldn't buy a pair of 225's without having them checked out completely by a mechanic. They can cost you big dollars. <br /><br />I would also check if it is an original pair from new and that the hours/repair history of each motor closely matches. Odd couples can be fine but expect suspicion when you go to sell and discount accordingly.