Outboard: Carburetor vs EFI

[Nomad Willy]

That's a peach of a boat there Art!

Ski another similar engine was the three cyl 55hp OMC. I had a Johnson on my experimental boat. Burned 3gph and needed next to nothing maint wise. Ran it a bit in the Queen Charlotte Is a bit then up to Juneau. Made several trips to Glaicer Bay and lots of short trips around Juneau. Then moved south and ran the boat on her bottom. Some running around the Everett/Marysville area and to Poulsbo ect. Hauled her out and in the spring she made it to the Skagit River Flats and the points gave out. Anchored and dinked to call my wife to bring tools. She ran perfect all the time. Loved the sound of the tripple working. Kind of an OB version of a Jimmie.

This engine had an electric solenoid shifter and it did'nt give trouble like some others did. I loved the shifter. Engaged the gear w probably less than 10% of lever travel. The large movement of the throttle made the engine a joy to control. Unlike my present 60hp Suzuki that requires extreme concentration to half gracefully run the boat. It uses about half the throttle movement to just shift. And I'll bet the 60 weighs 150lbs more than the 55. The 55 burned considerably more fuel but being a looper was better than most all the older tech engines of that day.

 

[Art]

That's a peach of a boat there Art!

Thanks, Eric.

Back in the day... One of the best and most fuel efficient Johnsons I had was 1964 model on 1962 13'3" Boston Whaler. Great engine!

 

[FF]

"Back in the day... One of the best and most fuel efficient Johnsons I had was 1964 model on 1962 13'3" Boston Whaler. Great engine!"

Which could have its carb cleaned with no parts required , and repaired anywhere in the world.

EFI is great , but it requires a dealer to fix.

 

[Art]

"Back in the day... One of the best and most fuel efficient Johnsons I had was 1964 model on 1962 13'3" Boston Whaler. Great engine!"

Which could have its carb cleaned with no parts required , and repaired anywhere in the world.

EFI is great , but it requires a dealer to fix.

Our current "Loop Charged" 1975 50 hp. Johnson o/b is very similar to the 1964 40 horse I mentioned a few posts previously (and is quoted in post above) ... in that... we use it at will with no big problems. So far. while nearing a decade of play time, it's needed a new seal for low end fluid, new starter, semi annual low end fluid change, new spark plugs, and a new impeller about every three years. Not too shabby for a now 41 year old o/b that powers our tow behind [1975] Crestliner runabout at 3300 +/- rpm doing 25 knots on (often multiple) cruises of fifty or more miles each, nearly every time we're out and about on our 1977 Tolly.

"Old School" builds and mechanical items are also "Good School" builds/items if correctly chosen for sturdy initial manufacturing-build-out, good prior-owner maintenance, strong remaining condition... and then of course... good continued care with thoughtful usage parameters. Using only in freshwater is also great for o/b longevity.

Fred's correct! - "... carb cleaned with no parts required , and repaired anywhere in the world.

EFI is great , but it requires a dealer to fix.

 

[Tom.B]

So are there ANY options for small outboard below 10HP with EFi?

 

[Marlinmike]

You really can't beat an old school 2 stroke outboard for a dingy, the problem is they haven't been sold here in the US and Canada in a long time and the used market is getting light in addition many were run in saltwater for over 10 years.
Having watched many a dockmate buy these nice shiny (insert brand) 4 strokes with carbs to only have to bring them back under warranty for carb work (told the EPA tolerances from leaning out is the issue).
With that when we bought a new rib along with plenty of research went with the 20hp Suzuki EFI and I have to say not one issue (knock wood), one pull and that's it. Like when cars went from carbs to EFI there was plenty of nay sayers, since I have an old 70's car in the garage and newer Honda's, there is no way anyone would stay with that technology today.

 

[Art]

IMHO - Whenever looking into purchase of older o/b, be it carbed or EFI, it is best to learn weather it was used in freshwater or salt water. If used in saltwater... then to be sure the engine was well flushed clean with fresh water immediately after each usage. Also, IMO, if an o/b was left sitting in salt water for much time without being in raised position - "Forget About It"!

 

[ranger58sb]

So are there ANY options for small outboard below 10HP with EFi?

The new-ish Suzuki DF9.9B is EFI. Same platform as the DF15A and the DF20A.

Used to be 2-stroke 10s/15s were built on the same platform, but 4-stroke 8s/10s were on one platform and 15s/20s on another. Suzuki combining 10/15/20 on the same platform is a little unusual. Also means the 9.9 weighs the same as the 15 and 20. OTOH, the 15s/20s are (last I checked) lighter than competition 15s/20s.

-Chris

 

[smitty477]

Due to an unusual set of circumstances I ended up owningmore than a dozen outboards over the past 10 years or so.
While none of them were new many of them had extensivehours on them and were used often and not babied.
Some of the 2 strokes we had included 2, 3.3, 8 and 40hp. Some of the 4 strokes we had included a 4,40 115 and 150's.
Over all of these units used I have had to rebuild carbsat a fairly constant rate especially which is a pain and can be very awkwardwhen cruising - especially the triples. In all that time and all of myexperience I have not had an FI failure or any sort of issue with thosesystems. Each season we cruise with a "paper' boating club which includesat least 30-35 boats on 2-3 cruises a year. Since most all of these boats haveinflatable's/dinghies with similar outboards we can extend our experiences toinclude the fact that none of them experienced FI failures but many if not allhad carb rebuilds. I won't even try to get into the comparisons of the carbedvs fuel injected or 2 stroke vs 4 stroke units.
When we cruise we like to find places to anchor out thatare quite and not just visit marinas. One of the typical places that we visitis Hamburgh cove off the Essex river and others like it. I really like to takethe dinghy out both late at night and early in the mornings when the water isflat and maybe there is just a light steam coming off the water. I have foundthat starting a carbed two stroke on those occasions to be a real let down astheir noise wakes folks up, the smoke drifts over the area and the oil slickdisperses out along the waterway. On a number of occasions I was carrying a40hp carbed two stroke on the boat deck and also towing a 115 FI four strokebehind the boat. There was no question which I would select to go for anexploration or a trip to shore as the FI four stroke was almost silent,produced no billowing smoke at all and never left a slick.
Similarly I still have one carbed 'hotrod' in my garagewhich has and does require carb attention at least yearly but in the past 20plus years since fuel injection on the rest of my vehicles I have yet to see anFI failure.
Just one persons experience and a data point to add toothers.

 

[koliver]

IMHO - Whenever looking into purchase of older o/b, be it carbed or EFI, it is best to learn weather it was used in freshwater or salt water. If used in saltwater... then to be sure the engine was well flushed clean with fresh water immediately after each usage. Also, IMO, if an o/b was left sitting in salt water for much time without being in raised position - "Forget About It"!

Art

I don't have the same fear of salt water.
I have had OBs in a salt environment since my first, bought in 1978. I have owned a fresh water flush attachment, which I used for a while on a used Johnson 15. thae OB dies a natural death, despite being flushed regularly. The circumstances of my moorage changed, I got lazy, I misplaced the flushing attachment and forgot about it.
Now, many years have passed, with 4 OB engines hanging off of my transom the past 35 years or so, never getting a fresh water flush. I have had no issues related to whether in salt or fresh water. My only issues were with carburated engines and ethanol in the gas. Now, with EFI, I have no issues at all.

 

[ksanders]

This has been a really interesting thread.

As a guy that is currently in the market for a new small outboard I have read, and re-read the posts here.

The big take away I have, as admittedly a non "expert" on the subject is the very high percentage of people that have had carburetor issues. Even the people that like carburated engines seem to indicate that they have gotten proficient at removing, rebuilding , or otherwise screwing around with their carburetors.

That just does not sound like much fun to me. Honestly screwing with a carburator, especially if it was a hours long job, just to get a skiff running is unacceptable.

I have an Evenrude 60 hp EFI engine on my pontoon boat. What a great engine. I've had that pontoon boat for over a decade. It sits in the water from April to October, and gets ran several times a week. It sits on the hard for the rest of the year.

I have done NOTHING to that engine except change the fluids and filters. Nothing! It starts and runs perfect every time. In the spring after sitting for several months it starts right away. I don't put special stuff in the gas. I don't do anything to it.

Thats the kind of reliability I am after in replacing the engine on my Whaler. Thats why I have decided to go with a EFI engine.

 

[Art]

Art

I don't have the same fear of salt water.
I have had OBs in a salt environment since my first, bought in 1978. I have owned a fresh water flush attachment, which I used for a while on a used Johnson 15. thae OB dies a natural death, despite being flushed regularly. The circumstances of my moorage changed, I got lazy, I misplaced the flushing attachment and forgot about it.
Now, many years have passed, with 4 OB engines hanging off of my transom the past 35 years or so, never getting a fresh water flush. I have had no issues related to whether in salt or fresh water. My only issues were with carburated engines and ethanol in the gas. Now, with EFI, I have no issues at all.

That almost sounds to be an issue... in and of its own volition! :lol:

 

[Heron]

Use this stuff...Regardless. It's pretty amazing.
My 20 year old Honda 2 hp thanks me every day...

Mechanic In a Bottle | B3C Fuel Solutions

 

[ranger58sb]

Haven't ever had much luck with the various gasoline treatment products versus ethanol. Including the several recommended by various sources over the years. None have seemed to actually stop separation, and that whole "absorbs water" thing always seems to go south in the carburetor.

I suspect I'm complicit, in that we don't run the outboard often enough to cycle gas frequently. Therefore I've gotten into the habit of dumping all our outboard gas into a car after about 2 weeks or so of non-use in the dinghy.

Mounting a fuel-water separator on the dinghy would be an easy-enough project, and Racor makes a likely snap-on candidate for that kind of application, but I haven't gotten a round tuit.


As a kind of test, I didn't try to run the injectors dry on our 15-hp Suzuki EFI when we flushed it and prepared for storage over last Winter, and the motor started on the first pull when we launched it last Spring. That was impressive.


Would have been more impressive if I hadn't let the starting battery discharge itself too low over winter... 'cause then I wouldn't have to "pull" the starter at all!

-Chris

 

[Ski in NC]

I don't think it is a good idea to try to run an EFI outboard dry prior to storage. It really does not drain like running a carb dry, engine will stall when fuel pressure goes low, but system is still mostly full of gas.

EFI is sealed from outside air so gas tends to not degrade from evaporation or oxidation.

My family had an EFI Yamaha 4s 150hp that would sit for six months at a time. When set up for storage, just flushed it on the hose and turned it off. No attempt to drain or run out of gas. We did this for like six years and engine always started right up when taken out of storage. Never a fuel issue. Truly impressive compared to carbs.

 

[smitty477]

FWIW - Mechanic in a bottle = 97% naptha and trace surfactants and masking agents.

 

[smitty477]

"My family had an EFI Yamaha 4s 150hp that would sit for six months at a time. When set up for storage, just flushed it on the hose and turned it off. No attempt to drain or run out of gas. We did this for like six years and engine always started right up when taken out of storage. Never a fuel issue. Truly impressive compared to carbs."


I agree 100% Ski - we have had a few of these and they always stored and started really easily. We do drain the VST tank as part of the normal winterizing process but when we did not it would always start immediately.

 

[ranger58sb]

I don't think it is a good idea to try to run an EFI outboard dry prior to storage. It really does not drain like running a carb dry, engine will stall when fuel pressure goes low, but system is still mostly full of gas.

Yeah, had read that, and that's kinda what I was trying to confirm. The manual is sorta silent on that. Says to add a stabilizer to the fuel, flush the raw water passages, and then stop the engine. Nothing more about the fuel system and storage.

So I "gathered" running it dry at least wasn't necessary, but knew nothing about whether verboten or not.

Our first year winter storage prep was by the local dealer, more as a matter of convenience for that particular year since we had some other life stuff going on. So last year was my first rodeo on this one...

And then I read about not bothering to run dry, tried it... seems to have worked like a champ.

-Chris

 

[smitty477]

I have found following the handbook and workbook to be very easy and effective for most any outboard. Most of these are available online for free or very inexpensive - Yamaha is quite easy to access online.

 

[Art]

Regarding o/b's with small fuel tanks:


I've had no EFI outboards; not yet anyway. From all reports they sound good for starting easily. Also have heard horror stories from those who did run into problem with EFI apparatus and tried to self-remedy (fix) the situation... take-it to a shop was end result, and rather expensive.


I've found using Berryman B-12 Chemtool on a regular basis added to gasoline keeps carburetor as well as other fuel line items internally free of build ups. I've yet needed to rebuild or replace an o/b carburetor - that's from 1960's to now.


Regarding inboards with larger fuel tanks:


Gasoline water build-up and Ethanol/Dinosaur fuel separations as well as critters growing in gas/diesel tanks that hold fuel for longer (six months to couple years) durations...


I've found that Soltron does the trick for keeping gasoline in good condition. Gas tests in clear bottle poured from my engines' canister filters always tell the story. As well as my engines' easy, quick start and smooth running at all rpm levels.


From what I understand Soltron works just as good in diesel fuel too.


https://www.navstore.com/soltron-en.html


BTW - I get Soltron from local NAPA auto store. Minimal amount of Soltron needed to be added makes it an easy application and considerably affordable fuel-safety measure for whenever adding fuel to tank.


As an aside - I don't bother to add Soltron to our 6 gal o/b tanks because their contents are gone through so quickly. And, If I were to take extended cruise on our Tolly where we were depleting, then refilling the tanks on a regular basis I would use 1/2 recommended amount of Soltron. When our 100 gal tanks are down to 1/4 level (25 gals each) I add can of Berryman B-12 Chemtool for internal fuel line cleaning. Then, when the tanks get to 1/8 level (12.5 gals) I add gasoline in what ever amount desired... full-up or otherwise! And yes - I have fuel level measuring device that gives me "exact" content level in each tank.

 

[Dazed and confused]

Figured I'd resurrect this topic rather than create a new one.

Assuming proper maintenance, what kind of difference in lifespan could I expect from an EFI Mercury vs. a carb mercury?

Currently using 15hp merc four stroke, something like 750-1000 hours/year. Would love to make the next purchase a 25hp EFI mercury.

What changes in maintenance/parts should I expect, cost and frequency wise?

 

[RT Firefly]

Greetings,
Welcome aboard.