Are 4-stroke carbureted Stern drives bring down the industry

[dingbat]

At the segment level, while most boating segments have demonstrated improvements in quality since 2007, both the small and large runabout segments experienced declines, with the small runabout segment experiencing the most considerable drop in quality.

"More than 40 percent of reported problems in the small runabout segment concern the engine and propulsion, which is primarily driven by the high concentration of four-stroke carbureted sterndrive engines," said Markusic. "Outside of the small runabout segment, only 15 percent of sterndrives have carbureted technology. However, within the small runabout segment, 80 percent of the sterndrive engines are carbureted. Considering the high penetration of carbureted engines -- which on average add 57 PP100 to a brand's score -- it's easy to understand why this segment receives such poor quality scores."

http://money.cnn.com/news/newsfeeds/articles/prnewswire/LATH01114022008-1.htm

 

[lrdchaos]

Re: Are 4-stroke carbureted Stern drives bring down the industry

I really don't know, why this day in age someone would buy a new engine that was a carb......
If money is that tight you can't afford the efi, you probably don't need a boat.

 

[tashasdaddy]

Re: Are 4-stroke carbureted Stern drives bring down the industry

most are begining boaters, who don't know better. the more reason for this free forum. they don't know better, don't know how to properly maintain the engine, outdrive or the boat, or operate the boat.

 

[lrdchaos]

Re: Are 4-stroke carbureted Stern drives bring down the industry

Absolutly......I've learned so much on this forum the past week....I've already reconized some things I did wrong when I bought my boat last yr. When I was considering a boat....I looked at it the same as a car, I wouldn't by a non-fi engine in an automobile and I wouldn't in a boat.

 

[John_S]

Re: Are 4-stroke carbureted Stern drives bring down the industry

Hmm, sounds like most buyers would disagree.

within the small runabout segment, 80 percent of the sterndrive engines are carbureted

 

[QC]

Re: Are 4-stroke carbureted Stern drives bring down the industry

You can't buy a non-FI engine in a car . . .

There are still a lot of people (on this here forum) that prefer carbs. I am not one of them, but at the boat show the salesman will say that this here 140 horse will run 50 MPH and get great fuel economy and it is the latest technology. It's sad, but true, and I'm a salesman. A lot of crappy guys choose my profession . . .

Personally I don't think it hurts the industry. People with enough passion to really be involved will find a way to move up. Those that don't, could buy a $85,000 Cobalt and still end up leaving it in the garage . . .

 

[lrdchaos]

Re: Are 4-stroke carbureted Stern drives bring down the industry

I just wonder why the boating industy hasn't stepped up and stopped offering carb engines? Just about every other industy has. I guess just cost... I agree with the above post. When I bought my boat I talked to salesmen that would tell me that the 4.3 carb would perform just as well as the 4.3 mpi....Until I test drove a few boats I didn't know. Just like salesmen selling underpowered boats, some of them don't care as long as they meet there quota.... In the end, I'm glad I spent the extra cash on the upgraded engine and drive, 8 people inthe boat and me slalom, still rips me out of the water. I'm pretty sure I have a parachute that I'm dragging, I don't know about...as well.

 

[QC]

Re: Are 4-stroke carbureted Stern drives bring down the industry

I guess just cost...

Bingo. That and emission regulations allowed it to continue . . .

 

[External Combustion]

Re: Are 4-stroke carbureted Stern drives bring down the industry

There are more reasons than initial cost for preferring carb engines. Economy, power and emissions for carbs can match injected engines although it is harder over the power range.

The carbs are much easier to get back running in primitive conditions and they will be easily overhauled long after the injectors are no longer available.

Most of the new Section 8 houses around here are total electric, but I think it would be a serious falt in logic to assume that the reason the houses have a high delapidation rate is due to their being all electric.

Starter homes and starter boats still have neophite owners and their mistakes.

 

[pine island fred]

Re: Are 4-stroke carbureted Stern drives bring down the industry

Guess I am in the minority but if find nothing wrong with a carb. I can hold it in my hand, see it work and fix it. FRED

 

[tommays]

Re: Are 4-stroke carbureted Stern drives bring down the industry

Problem NUMBER ONE starts right with the NMMA and promoting boating as a carefree activity like taking your car for a drive in the country

Problem number TWO is that GREAT lengths are gone to to hide the true cost of owning and keeping a boat maintained

Problem NUMBER THREE is unqualified dealers selling boats they lack the ability to service

i could keep going but it is to easy as the industry just shoots it self in the foot so often


Tommays

 

[erikgreen]

Re: Are 4-stroke carbureted Stern drives bring down the industry

For me, I went with a carbed engine instead of MPI because that's what was originally in the boat, and cost.

If you're doing your own work on an older boat, retrofitting for a MPI system is not cheap. My replacement motor cost me about three times what I paid for the boat hull, even using all the old parts I could.

Of course, I've probably spent more than that working on a refit since then, but I digress

Erik

 

[QC]

Re: Are 4-stroke carbureted Stern drives bring down the industry

Economy, power and emissions for carbs can match injected engines

Do you have examples? I must preface this by noting that I am in the engine/emissions business. Almost all heavy-duty diesel, but I am very interested in low tech solutions to high tech problems. My understanding was that it is very difficult to handle cylinder to cylinder combustion variations without MPI. Maybe you're talking about one carb per hole?

 

[Silvertip]

Re: Are 4-stroke carbureted Stern drives bring down the industry

Put most people under 40 years of age into a carbureted car and they probably couldn't start it. That is also an issue with many boat owners today who are first time buyers and generally don't know which end of a screwdriver to hold. There is nothing inherently wrong with a carburetor. Yes, they need to be rebuilt periodically but that's just part of the joy of boat ownership. If you have a carb issue on the water there is a fair chance it can be fixed to the point where you can at least limp back to port if you have some basic skills and knowledge of the boats systems. If an EFI system takes a dump you have no option but to look for a tow -- oh yes, and get out your wallet. I too think the marine industry is way overdue on switching to all EFI (even a simple throttle body EFI would be better) but a carburetor does not translate directly to a poor quality image in my view. Shoddy, inept, and dirty dealing sales and service teams are more to blame.

 

[JCF350]

Re: Are 4-stroke carbureted Stern drives bring down the industry

Do you have examples? I must preface this by noting that I am in the engine/emissions business. Almost all heavy-duty diesel, but I am very interested in low tech solutions to high tech problems. My understanding was that it is very difficult to handle cylinder to cylinder combustion variations without MPI. Maybe you're talking about one carb per hole?

Boy!, are you guys in for some fun. The EPA is just now setting their sights on the diesels.

In the days of TBI, continuous flow, mechanical injection and other such devices Carbs where actually more efficient at metering the the fuel at their designed flow rates however once you got out of those flow rates it was a tossup. MPI gives you a controlled amount of fuel at the back of the intake valve at the correct time to keep fuel from clinging to the intake surfaces and also reduces puddling.

Cylinder to cylinder variations require more than just MPI however. Pretty soon your going to see "spark plugs" that will measure combustion chamber temp, compression and vary the spark gap plus who knows what else by the time it reaches the mainstream.

 

[dcg9381]

Re: Are 4-stroke carbureted Stern drives bring down the industry

As stated above, the marine industry hasn't been forced to EFI because emissions are largely unregulated. They want to sell the most boat at the lowest price (to be competitive) so they continue to slap a cheap $400 carb on them, instead of $3k of EFI equipment.

I don't think you can get EFI efficiency out of a carb - the atomization simply isn't there... EFI fuel maps allow more than 144 points of adjustment (12x12 is pretty basic) - where as a carb has a limited set of jets and adjustment screws... You could get close with a carb, but I'd wager that generally speaking the EFI motor will make more power, run better, and be slightly more efficient at RPM.


EFI engines run great, I'd put up one against a carb for longevity any day of the week. They are expensive to repair and require special tools.. but the newer MPI systems have more and more self-test capability in them and really lend themselves to helping the mechanic rather than hindering him/her. They'll become less and less of a mystery and get more "consumer" friendly as they become standard.


The only case where I wouldn't want an EFI motor is probably industrial applications or a boat where I was doing long extra-costal trips... In those cases, I need to be able to find parts.

 

[External Combustion]

Re: Are 4-stroke carbureted Stern drives bring down the industry

QC: I would be happy to dig out a reading list for you and if you want I'll PM the start of one , but I think it would bore most here.

Note I did not say carbed engines were more efficient but that they can match FI engines at any given output, speed, temp or whatever. It is more difficult. FI engines made stratified charging much easier. It can still be done in carbed engines with mechanical means in chamber design as well as researched, thought out manifolding.

Atomization is there with carburettion, but at a higher temperature. Once again carbs need more thought instread of just dialing in a pulse pattern on an injector. Both systems suffer from the heavier particles of fuel being seperated from the lighter ones at speed. Carbed systems have more time between the atomization and the burn to get them remixed.

The final good reason for carbed engines is that short run engines will have much cheaper replacement fuel systems, both in the original and in the repalacement parts venue. That is significant for small marine engines as most do not reach the high volume status in manufacturing. 100,000 units is not a high volume run.

Both means of adding fuel to the air are good aproaches. Both will still be around long after all of us reading this this week are in the ground.

 

[QC]

Re: Are 4-stroke carbureted Stern drives bring down the industry

Boy!, are you guys in for some fun. The EPA is just now setting their sights on the diesels.

My career has been primarily truck; rest assured they've had their eye on us for a while. Today's (2007+) truck engines have either Exhaust Gas Recirculation (EGR) or Selective Catalytic Reduction (SCR). These strategies are coupled with an Oxidation catalyst or particulate trap or both. When I started in the biz (1977) we ran at 12 grams NOx per horsepower-hour, 8 in CA, that went to 6 in 1990 then 5 in 1994 then 4 in 1996 then 2.5 (combined with non-methane hydrocarbons) in 2002 then 1.2 in 2007 and eventually .2 in 2010. Every single one of those levels was considered impossible at the time they were announced. I may be off a gram or year here or there . . . Anyway, off-road and marine I believe are still in the 12 range as that is the sweet spot for efficiency, I'll have to double check that as there is a non-road standard now, but I recall it was pretty easy compared to on-highway. The industry has spent Billions getting to where they are and all of that experience and technology is transferable to any diesel application.

Oh, for what it is worth, SCR is the injection of Urea (cow ****) into the exhaust. This of course requires a tank and an injection system and cow **** infrastructure It is primarily used by the European manufacturers at this point, but it allows them to set the base timing back to the 12ish number (again 12 grams of NOx/hp/hr). NOx has been the biggest challenge for diesels. Spark ignited, lower compression engines, at perfect (stoichiometric) fuel to air ratios (why you have an O2 sensor) deal with NOx very well when coupled with a three way catalytic converter (your gasoline car). In the case of a diesel, NOx is directly linked to ignition timing. If you retard the timing, which cools the combustion event, NOx drops, but so does efficiency . . . So like it really sucks to screw up a perfectly perfect engine system on purpose, but that's what we do . . .

 

[azlakes]

Re: Are 4-stroke carbureted Stern drives bring down the industry

I really don't know, why this day in age someone would buy a new engine that was a carb......
If money is that tight you can't afford the efi, you probably don't need a boat.

... cause in most cases its a 2 or 3 thousand dollar upgrade. for people like you that seems to be chump change. thanks for taking everyone who can't afford the efi out of the enjoyment of boating.

 

[lrdchaos]

Re: Are 4-stroke carbureted Stern drives bring down the industry

... cause in most cases its a 2 or 3 thousand dollar upgrade. for people like you that seems to be chump change. thanks for taking everyone who can't afford the efi out of the enjoyment of boating.

Trust me it's not chump change, and I was in no means trying to take the enjoyment out of boating. But I would be willing to bet, in the overall cost of the boat in the end, the efi will be cheaper, unless your a mechanic. I hope my post didn't offend anyone, those are just my views. And I wouldn't be suprised if they mandated that all engines be fi that the base mpi wouldn't be close to the carb price. They know they will still have to have a base boat and that they can't increase the price that much or they will price themselves out of the market.