EFI vs Carb?

[diello]

I've come across a lot of boats with EFI with 400+ hours on them, and I've come across a few boats with less hours (ie. 120hrs), but with a Carb. All else being equal, would you recommend an "mint" Carbed engine with low hours, or a newer EFI engine with higher hours for reliability and general maintenance?

[woodboat]

Hours alone are not enough to judge. With that said a proper EFI should provide a more accurate fuel mix and longer engine life as well as efficiency. Carbs on boats are often a little rich as it is safer being a little rich than lean. In the long run this washes the cylinders a bit, more blow by and contributes to carbon build up. So..... for me if everything else truly were equal I would choose the EFI.

[nevd]

I have used a carburetted and a fuel injected 50 HP Tohatsu on the same boat and was surprised to see the TLDI being 8 kph slower. The dealer says there is nothing wrong with the TLDI, it produces less power than a carburetted engine and that causes the speed difference. What is the experience of others?

Thanks

nevd

[PowerTech]

to hell with a carburetor.EFI is the way to go less old timey BS.all of that tuning and BS let the computer do that for you.and better feul economy also.So if you are going to have a POS gas engine it sould at least be a efi.

[woodboat]

Is it safe to assume we are talking I/O based on an American V8?

[gonzo]

Nevd: 50HP is 50HP. That dealer is making it up to cover his ignorance or laziness. I am a NISSAN dealer which are the same motors. It should give you the same or more speed. If not, something is wrong.

[nevd]

Gonzo,

Thanks for your comments on TLDI performance. How can I get more information on TLDI setup as the dealer has experience with racing 50 HP motors? Dealer says unless modified, TLDI motors will never keep up with a carburetted engine.

Also the motor will not allow a Navman sounder to operate unless it is connected to a separate battery because of the A/C ripple voltage caused by the voltage regulator/rectifier. We were told this was a problem with the A model so the, we paid to upgrade to the B model voltage regulator/rectifier. The sounder will still not run unless connected to a separate battery. Your experience and comments here would also be appreciated.

Thanks,

nevd

[cyclops]

I like Gonzo's idea. Try a different dealer. EFI is usually locked into the power curve by the maker. Right or wrong, you can't change it safely. Carb's can be trialed and errored till you get it right. Don't even think of the$$$ difference of a computer to a carb.

[marshmat]

50hp SHOULD be 50hp..... in reality it seems one can label anything between 46 and 54hp a Fifty. This goes for most large outboard engines- for a while the Merc 90 and Yamaha 100 were identical, both 96hp in reality.

Having had all sorts of trouble with carbs having to be adjusted for different seasons, altitudes, etc. I'd gladly take an EFI engine over a carb one, even if it did have a few more hours on it. The better fuel mileage alone is great- not having to tinker with the darn idle jet, not spewing smoke, etc. are also benefits. Outboard or inboard, however rigged- I'll take a well-programmed computer over tinkering with carbs anyday. (Except for FICHT, of course, but that's another story...)

[cyclops]

Diello. Do you want to race or putt putt? Have loads of unneeded money?

[nevd]

[quote=marshmat]"50hp SHOULD be 50hp..... in reality it seems one can label anything between 46 and 54hp a Fifty."

Marshmat, this may be part of the problem. Dealer says 50 TLDI is approx 51 HP and carburetted 50 is approx 54 HP, but performance difference indicates about 10 HP difference.

Like your suggestion of going to a different dealer, but there are not many with TLDI experience and test gear.

I would be interested to hear the experience of others who have gone from carburetted to EFI outboards.

[cyclops]

If you like to adjust carbs and ign. go carb. Just turn the key and do the same speed as all others, go EFI. EFI's are obsolete very quickly and some are already non existant. Changing EFI's is a $3,000 to $10,000 expense for single or twin engine change over. On used EFI boats age makes itself known by the endless changing of sensors, plugs, sockets, corroded pins, brittle wire harness and the Computers do die. New boat, EFI. I have a 5.0 carb so I can always manually choke it enough to get back.

[mackid068]

Fuel injection is much more efficient and EASIER to use. Carburators are annoying to deal with. Even I know, and I grew up after carburated cars went out.

[Mykul]

[quote=marshmat]"50hp SHOULD be 50hp..... in reality it seems one can label anything between 46 and 54hp a Fifty."

I totaly agree with this, BUT, not all engines are created equal. a 50hp motor can be overall more powerfull than another 50hp motor. As 50hp is taken at a a certan rpm (5500). Unless you look at the power curve and compare it to the other motor you will not know how much power it has compaired to the other.

[Willallison]

Just back to the orginal question.... Outboard development has basically taken 3 quantum steps. You start with carbies. Then EFI. Then DFI & 4-strokes.
So it really depends whether you want to operate at the top, middle, or bottom of the development envelope.