Carbed will be the worst, fuel injected or EFI would be better, and then an engine like an HPDI or Optimax would be even a little better. To have those engines or four strokes for that matter, it would need to be a repower which would be good for the buyer in most cases. If the engine has a stock motor on it, have the cylinders compression tested, if they are more then 5-10% of rated, stay away unless you plan to repower soon. Also, as far as HP, for the gulfstream, a single will be most fuel efficient, although most on here agree they would opt for twins over singles in most cases. Twin 150's would be more efficient then twin 200's. For the sailfish, twin 150's might not be enough hp but it would get by, i would go for 175's or 200's, I believe most had twin 200's or more. The sailfish will burn more fuel at cruise then the gulfstream will because it weighs more, and in most cases will have more hp. Not sure what your budget can swing, but finding a boat that has been repowered with a newer engine then a carbed engine would be ideal. If it seems the price difference is too steep for you, a carbed engine would be fine, but will cost more to run. If the engine is in great shape and you are not out everyday, even burning more fuel with a carbed engine may be cheaper then buying a boat with newer technology. You need to decide what your main uses are and how often you plan to use it, as well as how long you plan to keep it. Also, think about if you would be willing to repower or not down the road, if not, finding a boat with newer engines might be a better idea. Range is another factor, if you plan to fish near shore it is not as big of a deal, it will cost more but not keep you from reaching your fishing grounds, if you fish offshore, having a more fuel efficient engine will not only help with fuel costs, but will let you run further and come back with more fuel in reserve for safety. Hope this gives you some things to think about and possibly help make your decision easier.
