i agree 100%...much easier to lean the overly rich mixture (might even get a couple of horses doing it) than reinvent the wheel

listen butthead...
you are correct. its a tech forum and part of the advice that you get from people that actually know what they are doing is that you recognize what the scope of the project is from a technical standpoint. you post a question indicating an absence of knowledge of the most basic configuration parameters of a very very complex system and don't expect someone to say " gee are you sure you want to take your expensive motor that you obviously can't fix the most basic problems with a carb on and invent an electronic fuel injection system that you know nothing about to solve problems that you aren't going to solve with efi anyway "?

welcome to the forum, forest.

your engine still requires X amount of fuel to run...weather it be from a carb or EFI so bottom line you are wasting your time and $$ whatever you gain....and will be small if any..you could buy a whole lot of fuel !! now maybe you need to look at what you have...go thru your carb, tune up ?? basic stuff..bet your friends boats are not a fair compairison...H/P vs weight etc...

Will, if you are more concerned about mileage than anything what ezstriper is saying holds alot of truth, although you have to jet your motor to be safe at all throttle settings and ultimately end up with some spots that can't help but be rich in order to noot melt down somewhere else lets look at the math:
Lets say everytime your boat hits the water it cost your 200$ in gas, you lean it out 15% (which would be my realistic guess) and you save 30$ every time you take boat out. I know you only take our boat out 10 times a year or so, you are talking a 300$ a year savings at best. To do your efi conversion (I just did this as you know) you will spend:
600$ mefi controller and harness
500$ for 8 appropriate sized injectors
150$ for regulator
500$ for throttle body
400$ for fuel pump
200$ fuel rails
200$ to get manifold machined for injectors
150$ for gm two plug coil connector tbi distributer
75$ msd 2 plug coil
750$ for fuel line/fittings
You will spend at least 3000$ if not 3500$ to do it and thats assuming you get your "friend" with the faster efi boat to tune it for you (Which I am sure "he" would do for free for a small favor from misses diet pepsi).
Your payback would take 10 years easily, if you still want to do it you I will help you make it happen, Smitty
If you want to see where your afr's really are get a o2 bung in them lightnings and jet it down using a 02 sensor and you will save some fuel.

how rich does your engine has to be to be ''safe''...too rich is almost as harmful as too lean...my definition of safe :find the ideal mixture,and go up ONE notch.....just sayin...