Re: MPI to Carb ??
 

nash give me a call or give me your number mine is 203 913-5450

Re: MPI to Carb ??
 

In a car due to the partial loading on the engine at various rpms, EFI has a huge effect on fuel economy.

In a boat, that load vs rpm range is much, much narrower. So how much really with EFI save vs a well set up carb? Not much I would guess.

Re: MPI to Carb ??
 

I agree. Probably saves gas at low RPM but going faster, you need a certain amount of gas to produce HP, so MPI, EFI or carb, my opinion is it's gonna need the same amount of fuel... I'm old school but I'd choose carb... plus I'm able to work on it by myself...

Re: MPI to Carb ??
 

I switched to carbs this past year because I was tired of trying to get additional hp without any luck from my mpi's. I had a carb motor for 10 years prior to these engines. So, I knew some of the downfalls but were outnumbered by the positives.

Re: MPI to Carb ??
 

When I bought my boat the dealer talked me out of MPI and I'm glad he did. My carb,set up by Mr. Nickerson, it's perfect first time out 2 pumps hit the key and it's running. Rest of the day I just bump the key and it's running. The key to this equation is the carb set up and Mr. Nickerson has that key covered.

Re: MPI to Carb ??
 

I also have a carb on my 7.4L, 454. I grew up working with carbs, so they seem simple to me... rebuilding, adjusting, etc... EFI seems high-tech, but god only knows to to fix it.

The rebuild kit for my carb I did this summer was $150 dollars. Expensive, but I rebuilt/water-tested/tuned in a day. Now the boat starts perfect (three pumps when cold), idles perfect and flys at WOT. Best of all, no labor fees.

Tom

Re: MPI to Carb ??
 

I forgot to mention emissions is probably the single biggest reason EFI went into boats...and cars! Without EPA regs the automotive industry would have taken much, much longer to make the change.

As for me, I kinda don't care what comes out my boat's exhaust! :evilb:

Re: MPI to Carb ??
 

My boat is carbed, but it's equiped with a new fangled device to help start it when it's cold. It's called a choke.

Once I've started the engines first thing in the morning, they fire up before one full revolution of the engine the rest of the day.

Re: MPI to Carb ??
 

It could be quite a bit actually. Ever looked at the air/fuel ratios by cylinder on a carbureted engine? They're terrible, and they get worse with load. You have to richen the carburetor, so the leanest cylinder doesn't get too lean, and then the rest of them are wasting fuel.

One of the problems with the marine EFI is there is no air meter as you have on today's automobile engines, so any engine changes automatically result in the need for computer recalibration. They also don't have the level of onboard diagnostics cars do.

If automotive EFI is any indication, someday I think everyone will be using it in boats. Compared to carburetors, my automobile EFI has been infinitely more reliable and better running. I've never had to do a thing to any of my car EFI systems, but I've sure had a lot gasoline on my hands rebuilding and troubleshooting carburetors (yuch!).

Michael

Re: MPI to Carb ??
 

I don't have a choke and mine do the same thing :p :D :D