I'm looking for a 25' offshore with a 454.

I'm trying to decide how important a boat with the 454 MPI vs. the 454 carb is? Both are the 454 Mag.

Any opinions of one vs. the other? Also did Mercury overlap 454 carb production with MPI production? It seems like there are older model year boats with MPI and newer with carbs.

I really like the MPI, no hard starts, pump throttle, flooded etc.

Can the Carb motor be changed over to MPI, just fuel and air system. No changes to heads, cam, pistons, etc?

Ive heard of guys going from the MPI back to carbs, is this true?

I love carbs for their simplicity, price, and the fact that once properly tuned, theyll make as much power as any EFI system

my powerquest is the first boat I've ever had with mpi and if I can ever help it again...every other boat I own will also have fuel injection...it's a great thing to just turn the key and having the engine fire right up...like u had said...no flooded engines..no pumping the throttle...

my opinion, if you are staying stock get the mpi, if you are going to build the motor up it is cheaper with a carb but either way you woud be unbolting either one for a better carb and intake. mpi if you can wing it and if you are building the motor it dont matter either way.

Having had both 454 mags carb and MPI, i would never go back to carb, the horsepower is a little more with MPI, carb 365hp MPI 385hp, and the the smooth running engines right from cold start up, no pumping the throttle, no stalling prior to warm up, and I believe the fuel economy is a little better.

I really plan to keep the motor stock. What about switching the carb motor over to EFI? Can it be done, are the two motors the same besides air and fuel systems?

Ive owned both...

Personally, I like the extra power from an efi (350 hp vs 385 hp--HP at the prop for both) but would never buy one over another because of simplicity in starting the motor. Yes, I could fire up the EFI in 2 seconds and maybe it takes 10 seconds with the carb (only when cold) but otherwise they run the same. I must say though that the hassle of vapor lock (constant problem on hot days), O ring leaks at the injectors and computer issues (I had one die on me) really has me soured on the efi but maybe that was just my poor experience...

EFI is great until something goes wrong, then good luck. The only benefit of EFI is easy starting and the downside of the extra complexity outweighs that greatly. Go Carb.

Coldstart is quicker and easier with Fuel Injection, but you can put an electric booster pump on a carb motor to make coldstarts less of a hassle.

Hot days, vapor lock is more of a pain on a Fuel Injected motor.

Performance is same for an apples-to-apples motor configuration more or less.

MC