Carb vs EFI

Maybe I'm bringing up a discussion that is bad for this community if some respond with incorrect information or can't back up their thoughts with facts. Or maybe I'm thinking way too far into the future (as a millenial I'm always wondering how life will change in the next 50 years) or maybe I'm just dumb in terms of motorcycle mechanics but I got to wondering last night as I was adjusting carb floats and breathing in fumes of gasoline in my garage - mind you its still winter in Ohio! - will the carburetors someday become obsolete? If so it would be neat (as an owner of two XJ's) to have them around for many years to come and someday be riding a true piece of history. With care and devotion these bikes should be able to last forever I would think.

My bikes are older than me so yeah if you couldn't tell I don't have near the amount of experience as most of you guys do. Perhaps this thread is a stupid question all in all... don't know unless you ask!

 

for the most part, carbs are already obsolete.

FU

 

Agreed. The main problem is the lack of feedback in the combustion process. Which means that you have to make overall design decisions about how lean to run (for cleaner burning) vs how rich you run (for power and reducing detonation) to fit a range of operating conditions. Richer burning means more hydrocarbon and carbon monoxide emissions, and a catalytic converter has no chance of keeping up, which means lots more low level pollution that affect respiratory health. And these setting can easily change (and need to be adjusted) as the passages inside oxidize and get gummed up by fuel residue.

Carbs get the job done (they make the engine run), are easy/cheap to install. But performance-wise, they just aren't as good as EFI. Involving sensors in a feedback loop, adjusting the mixture for the current output, means cleaner, more efficient burning engines, with much less maintenance. The design is more complex, but once perfected, it's a system that works better and with way less maintenance that a carb. As costs come down and systems are further miniaturized, and there is more regulatory pressure put on small gas engines, carbs will disappear.

I've got a 1985 Simplicity Snowblower that I got off CL for $50 7 years ago. I rebuilt the carb and have run it for 3 seasons (had to clean the carb again this year since it went unused for the last 4) and it's throwing snow like a champ. It stinks tho, and in no way burns cleanly, but in a more rural setting, it's not a real problem. With all this snow in Boston, if everyone was running a 30 y/o snowblower, the effect on localized pollution would be significant.

You'd smell it in the air. You smell it every time a classic car takes off from a light. It might be a sweet smell for a garage mechanic, but it's something entirely different for the health of an urban population, and it's unavoidable for carbs. You don't seen any cars with carbs, all but the lowest end motorcycles don't have them, and you'll soon lose them on small engines too.

 

Not to mention the fact that a carb has a bowl full of volatile fuel, usually directly above hot exhaust parts, ready to leak out if not kept upright. EFI is safer too! On top of it all, you have evaporative fuel losses which will not happen in the closed EFI system.

 

I get your point MB12, and if 30 y/o snow blowers were more common these days then there would be a genuine problem in an urban or suburban area, but much like the classic car analogy there are so few still in use (regular or on Sundays only) I cant see that being an issue. I do agree, however with the trend to move small engines over to EFI in some way, as it seems more small engines of two and four stroke construction are tossed in the trash due to carb problems, rather than actual mechanical failure.
As to the bikes, well again how many do you see on the road vs modern bikes? I like carbs for a lot of applications, and vintage bikes are one of them.

 

Oh I'm not saying that all carbuerated engines must, right now, be replaced by EFI. I'll make no effort to "update" my seca and turbo seca to EFI. These bikes don't apply carbs to a vintage application, they were once a "modern" application for carbs. Modern bikes don't employ them, hence, carbs are already obsolete, as most production vehicles do not employ them.

But I hope to run them til the wheels fall off, I'm in no rush to replace them with modern machine. And I happily throw snow with my old blower. Heck, all three of these machines take a real knack for mechanical repair, just to keep them usable, and most people would just junk them and buy a new one. Even when "they don't make them like they used too." That's why I have them

As you say, most combustion engines will fall into disrepair, and then be replaced by whatever is in production now. And what is in production now, can be regulated by the EPA to reduce emissions. So sure, carbuerated lawn equipment will continue to last if maintained, but new equipment will soon be regulated to the point of requiring EFI to meet emissions standards, it's only a matter of time.

I only mentioned 30 y/o snow blowers to compare the then/now differences in design. Functionally, my old snowblower is fine for the job, the little fuel is wastes running rich has no impact on the cost of running it. It's also an L-head engine, vs the OVH engines of today. If designs hadn't improved over the last several decades, the pollution from greater use (increasing populations) in more congested areas really does add up. It only "hasn't" because of improvements directed at lowering per-unit pollution as more units are being produced.

The classic car example is just a taste of the past. I don't look down on the individual that can keep and old machine running, but I would look down on a system that doesn't improve technology to have less of an impact of respiratory health. EFI is part of that drive, as carbs can't meet that requirement.

And I mention Boston because I'm an hour west of the city, and the record snowfall means a lot of power equipment moving a lot of snow.

 

-Its very hard, if not impossible to beat the linear progressive feeling and throttle response of well set up Carbs versus EFI. I own two of the very best examples of that breed. A 1986 Yamaha FJ1200 and a 2002 Kawasaki ZRX1200. They are not hard to maintain really, and just need a little fine tuning from time to time. In the USA, Ethanol is a big issue with regards to clogging up carbs unless one keeps on top of that by making sure to have the relevant additives always in the Gas tank, and also regular use of the machine.

 

Rather than concerning yourself too much about the ``negligible``amount of emmissions coming from carbed bikes and classic cars, a better thing to regulate in America would be the infatuation with oversized engines which dominate the market there. These gas guzzling monstrosities throw out huge amounts of pollution , Cats, EFI or whatever notwithstanding, as well as depleting huge amounts of a finite resource such as Petroleum.

 

BUT....but...I tow a trailer twice a year, and pull people out of the snow all winter........

 

Yeah, we have some strange laws here. Somehow the Hummer and Dodge Hellcat can pass emissions regulations, but not a Honda Civic Type R. Which one do you think is the bigger polluter?