Carburetor versus fuel injected engines

[Pseudomind]

Carburetor versus fuel injected engines

I know there are many carburetor engines in use, bu tI am curios to find out from those who have carburetors if they think they might prefer fuel injected engines on their next boat

I have been considering a 2001 Sea Ray 340 which has fuel injection and also looking at a 1998 Sea Ray 370 which has carburetors. I am just wonder if I should go wit the 340 and fuel injection over the 370 and carburetors. I know in the automotive industry fuel injection has been a big plus over carburetors.

I am just looking for some valid opinions from others.

Thanks

 

[Hampton]

I don't know if I would let this issue help me make the decision between those two boats. If all else was pretty similar - condition, hours, accessories, price, then even though the carbureted boat is three years older, I may choose it due to the extra room available. If I were looking at two similar boats of the same age and same size, I would choose fuel injection in a heartbeat. One of my best friends has been fighting his carbs on twin 502's in a go-fast boat for years to avoid spending the $1400 for a new pair (of carbs).

On the one hand, carbs can be fickle. On the other, they can be tinkered with and/or replaced.

 

[bluebelly]

When efi broke in the marine industry back in 1996, I remember alot of promises about better fuel economy and ease of starting, etc. At the time I was on my third boat with, of course, carbureted engines and had no problems with reliability or ease of starting. Now that I have had 3 efi boats, I still cannot say they were much of an improvement when it comes to fuel economy. Yes, better horsepower given the same engine with carb., but not better fuel economy. I would say the efi starting reliability is not as good as with a carb since I have had a couple of problems with a crank position sensor and a Idle air control valve. These are two problems that could not have happened on my boat if it was a carbureted engine. If it were me I would not hesitate on the 370 if my only concern was that it has carb engines. By that year, caburetors were a very mature technology.

 

[Two Peas]

I've moved up this summer from a 215EC with a carb'ed 4.3 to a 280DA with twin EFI'd 4.3s. My experience is dramatic - although the carb'ed 4.3 on the 215 was reliable and always started easily, it pales in comparison to the ease of starting the injected 4.3s on the new boat. No throttling, no neutral revving, just a simple button push and they fire up immediately. I love them so far. As well, there's no "pause" in power when the 4 barrels open up... power is immediate and consistent all through the throttle.

I can't give any experience on maintenance yet, though.

 

[Hampton]

I can't give any experience on maintenance yet, though.

I can help on maintenance. I bought a 1997 SR 250 new in 1997. They offerred 7 engines. I wanted a different one. They offerred low and high powered FI and Carb'd in the big blocks, and low and high powered Carb'd in the small block, and a low power FI small block. I wanted the high powered FI small block, 5.7 LX EFI. They built it that way for me. I owned the boat for 10.5 years and it started every day, every time, and I never performed any maintenance on the FI.

 

[tsandu]

I went from carbed mercruisers, to efi mercruisers on my last boat, and back to carbed for my current boat.. When everything is perfect.. the efi was fantastic.. unfortunatley on boats, things often are not perfect.. and fixing and diagnosing efi issues was not possible without special tools (ie $$$ marine technicians etc).. with the carby models, they may not be as efficient, but they are pretty close.. they may take slighly longer to start up after staning for a few weeks.. however. you can pretty much diagnose, and repair most issues on the water with a small toolcase... EFI have to many sensors to brake, many electrical cables which corode, many connections which corode.. unless you have $$$$ to have a very experienced efi mechanic service and repair your boat often.. i'd stay away... this current boat i owned for 6 months, so cant comment.. my previous boat which was efi.. the first 2 years was okkay, however the 3rd year had a few things go wrong.. at the worst possible time.. was costly and a pain to get fixed.. the boat before that was carbied.. had for about 4 years.. always serviced myself from new... besides being harder to start then the efi.. had no issues.. all my services was only an oil change, spark plug change and filer change... with the current boat.. i am expecting a issue free, cheap to service next couple of years. Also i will add the efi had closed cooling.. and the carbied is saltwater cooled.. and still had issues with efi.. yet none with carbied mercruisers.

 

[J Levine]

I have had owned three boats over the last 15 years all with carbs and have yet to experiece any carb related problems. When I was looking for my 370 back in 2003 I only wanted a 95 model to avoid the first generation EFI 454's that arrived in 1996, not that those motors have been problematic, I just wanted somthing that was simple that I could easily troubleshoot and repair. I will say that we have another boat in the family that was purchased new in 1998 with a 5.7L Merc EFI motor and it has never had any EFI related problems.

 

[Pseudomind]

Is there a guide which tells what each engine comes with, How can I tell when only this is listed. I have only an ad to look at

1999 model 370 Sundancer with 380hp 7.4 MPI Gas

Is this fuel injected or not? Can one tell from the ad?

Thanks

 

[H2ONUT]

MPI = Multi Port Injection

 

[douglee25]

Here's the scoop....

Carb -

1. Def. easy to work on
2. Simple
3. Can be slow to warm up
4. Slightly less fuel efficient at trolling or sub cruise speed
5. Longer starts at times

EFI -

1. Can be harder to work on if you're unfamiliar with electronics
2. Instant throttle response - no warm up necessary
3. Fuel efficiency increase at idle or sub cruise
4. Instant startup

Some other points... Even though EFI is more complicated, they aren't that difficult to diagnose. You just need to understand them. In fact, it could even be said that they are easier to diagnose than carbs because you can plug in a scanner and it will tell you what's wrong. No guessing!! Again, you just have to understand EFI and not be afraid of it. As far as efficiency goes, EFI and carb will almost burn the same at cruise. Carbs are jetted for cruise mostly. Carbs will run richer at idle/sub cruise speeds where EFI will have more optimum fuel/air ratios due to computer control.

I wouldn't let the EFI or carb issue sway your decision.

Doug

 

[Dirtguy]

Ok. The EFI systems with Mercruiser had MEFI systems. Hang on here because this will affect many past threads on the IAC problem. ALL the IAC problems are because the algorithm had an "IAC reset" in the program. This means that since it's basically an industrial application that the IAC resets every 30 seconds . Reset means that it reseats and then full opens to locate it's position. This is to properly identify the amount of "bypass air" ingested to the sysem for fuel mixture. This is done because the spring drives the pintle to the seated position with the vibration of the engine.

When you power up the sytem, the IAC must again, identify the position. So don't go from off to start immediately or it might die.

Just a byproduct of EFI. Don't ask me how I know or I'll have to shoot you.

DG