Question to Spaniard King re Carby Versus EFI

[charleville]

Everyone on Ausfish respects your expertise on outboards, SK. So, your response to this question may be of general interest to others. The question is prompted by the other current thread re a Merc 60 HP fourstroke on which you have offered advice.

I also have a 60HP, four stroke, carbureted Merc that I have had new since buying my boat eleven years ago. I think that the motor is wonderful - quiet, economical, has never let me down. So in saying all of that, I may well have answered the following question but let's see what you think.

When I bought the rig, I was offered the choice of a carbureted model or an EFI version. At that stage the EFI versions were, if not new, still relatively early in their product life cycle and cost a couple of thousand dollars more than the carbureted model.

I made the choice to go with the carbureted model mostly because I reasoned to myself that the EFI models may have required test equipment that every marine mechanic off the beaten track may not have had and if, say, I chose to take the boat to one of these "off-the-beaten-track" places, I may well be stuck for repairs to have to drag the boat back to the big smoke. I reasoned that, conversely, every motor mechanic in the land would know how to work on a carbureted model at that stage.

As it turns out, I have never needed such contingency but now I wonder if there are long term benefits of one form of the motor over the other.

For example, a mate of mine bought a second hand boat from his own employee (ie a reputable source) with about a 200HP Evinrude Ficht on the back and had computer problems from day one, quite literally. He got out of the first issue with a second hand computer because no new spares were available. However, when the thing failed again, a couple of years down the track, without much hesitation, he spent $25 000 on a new eTec. In his own words, "That has been my worst decision ever" because as (bad) luck would have it, that motor failed early and he had to be towed home yet again.

This is NOT meant to be a thread about eTecs but rather about the longevity of EFI versus carbureted engines.

Sooooo.....the question is, what advice would you give to a buyer of a motor of about mine's vintage (say ten years or older)? Would you recommend one over the other, viz carbureted or EFI? Perhaps one is cheaper to service than the other? I have no idea about such things but I know that you do.

Many thanks in anticipation of your response. I don't have any purpose in asking the question other than curiosity.


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[Spaniard_King]

Charli, so as not to start an Etec thread I will only refer to 4 stroke engines in regards to EFi or carby, this is mainly due to the DFI 2 strokes being a totally different kettle of fish to a 4 stroke.

The japanese have come a long way since entering the 4 stroke market and there is no doubt the EFI engine is way more reliable and fuel efficient than the carby version. The late model EFI engine is based on automotive technology with years of research and developemant it is a very user friendly engine. The new breed has the ability to shut down the engine before it damages itself in the event of an overheat or low oil alert. it also has a safegard mode which alerts the user of a fault but allows them to drive home. non of this is available with the carby models. Also if installed properly is easy to service and should never require the use of the primer bulb unless the engine runs out of fuel or a leak in the fuel system exists. The later EFI engines have the ability to supply the user with greater engine management tools than he could ever want if coupled to a suitable NMEA 2000 display

Carby engine never seem to be void of fuel issues at one time or another, Injectors are a lot easier to clean and no tuning is required on re installation. The EFI engine has a prety good fuel filtering system which if maintained thousands of hours should be attainable without injector servicing

[charleville]

Thats a terrific, very informative response. Many thanks, Garry.


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[trymyluck]

One of the main reasons I went efi when I upgraded my motor and it may well be I'm wrong but I believe there is safety issue with efi engines over carbs when crossing bars or in large seas. Carby engines are more at risk of flooding.

[tunaticer]

Good response Garry.

[charleville]

when crossing bars or in large seas. Carby engines are more at risk of flooding.

I think that I read that recently in one of Spaniard King's posts also. Had never really thought of it before. I have not had that problem in Moreton Bay though, even though on a couple of occasions the conditions were more than a bit lumpy.


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[Spaniard_King]

One of the main reasons I went efi when I upgraded my motor and it may well be I'm wrong but I believe there is safety issue with efi engines over carbs when crossing bars or in large seas. Carby engines are more at risk of flooding.

Personally I think this one is for Mythbusters, I really can't see why a carby engine would flood in rough seas or crossing bars ( I beleive this was Lucky Phills philosophy)

Plenty of carby engines have crossed extremely dangerous bars with no problems, just remeber they have been around a long time.

[FishHunter]

I remember discussions like this when cars first went from points to electronic ignition and no one wanted a 4wd with electronic ignition for the same reasons as above. Then cars went EFI and the same argument raised its head again with no one wanting efi on a 4wd vehicles. Same thing happened again when diesels went turbo and common rail
Now its the outboards turn but that argument is almost dead already

[cormorant]

I'll add 2 bobs worth here.

Charlie - nothing wrong with choice or reasons and you've had a good run with it.

Boats due to thier fuel systems , usage and other conditions make them a special compared to other motors / vehicles. Unlike cars there just isn't enough volume so you are stuck with propietary parts prices for electric FI and DI parts. $1000 for a $22 computer or $400 for a $75 bosch injector in a different casing can hurt if you have problems.

There is EFI and direct injection ( DI) . EFI has fuel injector in the intake manifold ie a electronic controlled carby jet or multiple ones. Direct injection has the injector it in the cylinder head and require huge pressures to get it in. Cars are now moving towards direct injection just like diesels have been for XX years - like 100. It allows fuel to be injected with very fine droplest size and with modern electronics several times during a single stroke to create a very effecient burn and smooth power with tiny amounts of fuel.

Carbies don't normally cost thousands when there is water contamination. Carbies have many moving parts all of with can degrage etc etc. EFI, DI have a computer , high pressure fuel pumps

With EFI , direct injection you need to have the appropriate fuel system , filters and also suitable electrics set up.

With smaller motors there just isn't the fuel saving unless you are doing the hours but you may get hurt on resale as motors are becomming a fashion / status item and people like to see the latest technology on the back. A carby may last the life of the motor with a kit every now, require tuning and then but repeatably on Ausfish we see electonic systems failing and having to be replaced at huge cost and all the extra bits a EFI and DI require can be failure points. I am seeing some aftermarket kits for motors that will never comply with EPA but are producing large simple reliable HP from recent model powerheads. If manufacturers don't keep spare parts prices reasonable some people will go these kits rather than OEM.

Carby can varnish up and don't like sitting unused, moving parts etc etc and in will get harder to find good knowledgeable mechanics who will tune em properly. Time is money.

Lots of pros and cons .

EFI and DI for larger motors for me but with the proviso they are set up with correct extra fuel and battery systems and run often on good fresh fuel. How these motors will fare outside warranty in 10 years time will be interesting as opposed to so many who continiously upgrade boats and motors.
On large motors and large hours it is simple due to fuel costs

Motors breakdown or fail often from the simplest of issues and so often installation issues and parts that have reached the end of their usefull life like fuel lines , filters not being checked and replaced at correct intervals and the ever present water. Most problems are preventable with a proactive mechanic / owner at some stage and many are out of control of the user no matter what motor fuel delivery technology you choose but it costs to be proactive and relaible rather than have wait fro some items to fail.

Happy New Year everyone.

[FishHunter]

I'll add 2 bobs worth here.

Charlie - nothing wrong with choice or reasons and you've had a good run with it.

Boats due to thier fuel systems , usage and other conditions make them a special compared to other motors / vehicles. Unlike cars there just isn't enough volume so you are stuck with propietary parts prices for electric FI and DI parts. $1000 for a $22 computer or $400 for a $75 bosch injector in a different casing can hurt if you have problems.



Happy New Year everyone.

I disagree with that,most of the 4 stroke stuff seems to be based on dry sumped car engines so the numbers are there its just easier to charge more when you add "marine" in the description.

[JB]

Charlie i had the 2003 Merc EFI 60 and i must say the EFI was amazing... instant starting and never out of tune always smooth. I'm now onto a honda 60 EFI which is also fantastic. I remember our old 15 suzuki carby needing tuning and flooding.. what a pain.

Jas

[charleville]

Thanks JB. Actually, I have had the same experience with the carbureted model. I often find myself feeling very pleased at how the engine just purrs along when I am returning from a fishing trip in a relaxed mood. I am constantly wary of outboards though because they rev higher than cars and have a lot more carburettors to go wrong. Have never been unhappy with that Merc.


Of course, I get it serviced by professionals every year and don't overwork it in terms of revs so hopefully, I am doing all of the right things. Yes - I could change the oil etc myself but, in truth, I swim like a wind tunnel tuned lead sinker and so I am always happy to pay whatever it costs to get the motor serviced properly so that I don't need to call the VMR or test if I can out-swim the sharks.

[cormorant]

I disagree with that,most of the 4 stroke stuff seems to be based on dry sumped car engines so the numbers are there its just easier to charge more when you add "marine" in the description.

I don't think there is a definate answer without getting very specific. The smalest parts be it a valve guide may be the same or different depending on what failed , showed wear in their durability testing.

Yes they do use similar dimensions as they have years of knowledge of the peformance of those dimensions with production tooling to suit. They know the thermal loads , and all possible permetations of Hp , torque, revs etc. They haven't invented a motor and dynamics from scratch they have just changed the purpose of teh motor. The simplest issues of of having a injector on the side of a plenum to the top and resulting droplet size etc is a science in itself when they try and get effciency gains or similar numbers to existing automotive engines.

I know what you are saying and some companies have used it as a marketing tool like Honda to say it was a civic engine etc etc but in reality there are very few interchangable parts and they are very distant cousins at best. Even with the same bore pistons but have different coatings made from different metals , extra oil galleries different seals and the list goes on. Yep it may have been loosley based on the block casting but ......... Yet to see anyone actually do a parts list and confirm if / what parts are interchangeable apart from standard bearing sizes but again different quality specs can be used but you are right they are not manufacturing every single part in house from scratch. I don't know where teh line is and gouging begins as opposed to recovering development costs and making a decent profit.

The companies get smart like Evinrude who used to only sell a "in house manufactured tilt trim seal" "special o rings" with odd dimensions as a expensive kit and it took a few years before aftermarket manufacturers saw the margin involved and started making them as a individual part and Audi , Merc have done similar so you must buy original parts or kits or use special tools to access, undo a special inaccessable bolt. Big risk by aftermarket manufacturers with patents etc let alone tooling costs and bulk manufacturing to have thousands of a single company , single use seal hanging around in a wharehouse waiting for a buyer.

I know one motor that uses the same bosch injector as a mazda 121 and a new original mazda one is worth 600 odd and the marine equiv is only 400 odd but there is a heap sitting in motor wreckers if you knew. Bosch and other OEM manufacturers are getting very smart and numbering parts for individual companies ( even if identical) so you are never quite sure these days if the exact spec is the same to try and stop generic parts becomming cheaply avaliable on the back of the expensive development done by manufacturers.
Volvo for example will use a new part number for a new motor even if the same part is used in older motors and charge a "new higher " gold plated price for the later model part but have you over a barell unless you are prepared to take the risk, measure and test them to prove they are identical and often it is just a change in a subcontracted parts supplier not the specification.

The only engines I know that are fully interchangeable are on the longboats in vietnam and china where it is bolted on to the shaft.

All technology and designs are good while they are working but it is teh overall cost in it's complete lifecycle for the individual user that is the proof and that contains so many variables it is a hard call.

I wish we had a better system of USA JD power style survey to weed out lemons faster and hold manufactrers to account.

[tunaticer]

But when are the mainstream large outboard manufacturers going to develop a light weight turbocharged efi common rail diesel outboard???
The sooner we deviate from the hazards of petrol and boats the better.

[cormorant]

They don't own the technology in house so margins would be smaller and the large markets still have cheap petrol. The introduction of cat converters on 4 strokes in the future may have them one step closer using injected 2 stroke with wet sump technology. Boats now being built for heavier 4 strokes could take a lightweight diesel motor but the small market and number of hours for payoff will leave it in the commercial domain fo a while. The big issue will be particulate filters . Educating large markets like teh USA to buy a diesel will be pushing crap uphill.

Did you see the pod diesel jet outboards on a thread the other week? More ways to skin a cat.