Used Gulfstream purchase

[robcar]

I sold my 1996 228 two years ago, knowing I'd want a Gulfstream in the future. I stumbled across and bought a 2001 Gulfstream with Saltwater Series II 250 EFI engine. Got a great end of the season deal. Questions:
1. How will the 250 EFI compare relative to an equivalent Carb engine? I know this isnt apples to apples, but I'm hoping the fuel injection adds 20% oil/gas improvement over carb. I used to get about 2 mpg on the carb-228, but that was a smaller engine/smaller boat. I've heard its the same, to, its as good as a 4 stroke. Anyone with this combo that has mpg specs?
I'm also hoping for less noise and less smoke.

2. It has a porta potty. How much to upgrade to deck pump, macerator, or holding tank? I'm not very clear on details of these choices

3. The cushions are worn and the arm rest cushions need to be replaced which seems common with any used Gulfstream I look at. Where can I find replacements or clean used equivalents?

4, Any suggestions on Fishfinder/sonar combo? I like Hummingbirds products and I'm not so keen on Garmin after my previous experiences(thermocline never worked, fish symbols were wrong, Garmin had no answers or tech help). I'll fish LI Sound area mostly- never deeper than 200 feet.
4-A. Suggestions on good marine radio/speakers?

4. General question. My wife wants to be able to layout on the boat as she could with a dual console or center-in front. Anyone familiar with an portable bench that could suffice? Other solutions?

Thanks in advance for any responses. Glad to be back. I've tried other boats(Hydrasport, Proline, Seafox). Nothing matches GW...

 

[JeffN]

I only have a suggestion for question #3. Find someone local to make you new cushions. On my first replacement I purchased off the shelf cushions and they did not hold up well. My next set I had made and they cost only slightly more and still look new after several seasons. There are various grades of vinyl and foam, buy the better grades. No red mold that way. A good provider can steer you in the right direction. Ask around your marina, dock or ramp for recommendations for a good canvass guy.

 

[family affair]

You can call or email Grady for the performance test on your boat. If your set up is similar, your numbers should be close to what they got. If you aren't getting what they did, make sure your prop is properly cupped. If that doesn't work find a Yamaha 5 star tech to sort it out.
As for the smoke, even a properly tuned ox66 will smoke at start up until the O2 sensor gets hot and leans it out. After that smoke should be almost unnoticable other than the smell down wind.