Fuel injection vs. carbeuration?

[acidburn]

Is anyone not convinced FI systems provide the best fuel delivery for our toys yet?

[R111S]

FI is old tech now...we're driving an FSI VW Passat...very similar to a Diesel, and yes, much better than FI.

OTOH, I liked the jetting Bings on my Airhead...and I like the Bosch FI on my Oilhead...either is fine for me but when FSI comes to Motorcycles it'll be better than both.

[markjenn]

I doubt I'll ever buy another carb'd bike, even a dirt bike (whcih probably means I won't be buying another dirt bike or dual-sport for a few years). I absolutely detest taking the carbs off, screwing around with the brass bits, and cleaning gunk out of jets when you let the bike sit too long. I'll take electronics and fuel maps over brass jets, rubber o-rings, cloggable passages, tons of little parts any day of the week.

- Mark

[bradzdotcom]

mark~
many/most of the four-stroke motocross bikes coming in '08 will be fuel injected. other models will soon follow.

anybody who has ridden an FI bike next to a carb-ed bike at altitude, already knows that FI kicks butt.

(i once slogged a constant-velocity carbed goldwing over the continental divide...18mph for hours on end....once was enough).

diaphrams (and sucking) may work for birth control, but when it comes to motorcycles, you get screwed every time.

[throttlemeister]

Originally posted by R111S
FI is old tech now...we're driving an FSI VW Passat...very similar to a Diesel, and yes, much better than FI.

OTOH, I liked the jetting Bings on my Airhead...and I like the Bosch FI on my Oilhead...either is fine for me but when FSI comes to Motorcycles it'll be better than both.

Direct fuel injection has been around as long as fuel injection excists, so FSI is old tech too. It's just being marketed as new by VW with a fancy name. I don't see how direct injection has so many advantages in motorcycles, where every cylinder has its own (or multiple) injector(s).

[tomn]

My "71 VW squareback had an injector each at cylinder head, direct injection. nothing went bad. all my recent bikes had FI and nothing went bad, yet this April in Baja on my F650 I had incessant anxiety from FI. that if something goes wrong I could not easily fix it whereas if I had a carb bike, I would simply take spare bits and I could swap out. So almost all fuel side issues would be confidently dealt with. All systems have limitations and their places.

[roger albert]

You guys don't seem to understand what direct injection means.
It is not the same thing as per-cylinder.


For temp and altitude variations, FI wins hands down.
But there are numerous examples of crappily tuned injection (even from the factory) and great examples of carb tuning.
So in reality, it just depends.

[captainasty]

Yes Sir, direct injection has injectors in the combustion chamber. The others are in the intake port.

[throttlemeister]

Originally posted by roger albert
You guys don't seem to understand what direct injection means.
It is not the same thing as per-cylinder.


For temp and altitude variations, FI wins hands down.
But there are numerous examples of crappily tuned injection (even from the factory) and great examples of carb tuning.
So in reality, it just depends.

I understand perfectly what direct injection means. I just don't think the advantage of it is not as big in a motorcycle application where there are 1 or 2 injectors in the tb for every cylinder, as opposed to cars where a common rail type setup seems to be favored more.

[on2wheels52]

I fess up to the lone carb vote. I have several 20-30 year old bikes that run OK now, I'm hoping to be riding a couple of them in another 30 years. I'm not sure I'll be able to maintain a 30 year old FI bike.
Jim

[knnshallwminded]

i also prefer carbs .when set up right you dont have to mess with em.not to mention theres 8 lbs of wiring alone not counting fp computer relay boxes etc.to each his own.i have worked on fuel inj systems since 1974.am building a r1100s 99 from a wreck w 5200 miles .will be finished soon.have taken a lot of weight off it.running 45fsmickunis dyna 2000 digital suzukirace ignition custom47mm stainless exhaust d d cans.and some other tricks.once on road will post pics and specs after dyno.

[acidburn]

Cant wait to see that.

[zx9rmal]

In the beginning, when it was just Adam, Eve , and early FI, I was very skeptical. A lot of electronics to malfunction. But over the years, I've seen few FI malfunctions, and the state of the art is phenomenal. Any altitude, temp, or humidity, the bikes run smoothly without any fueling issues. The good systems provide seemless operation, i.e., instant throttle response, no lags, hesitations, SURGING (ahem!), flat spots, etc. You can keep, the smelly fingers, as well as needles and seats, float bowls, and pinched rubber diaphragms (the carb ones!). I will say I DO miss the tinkering that goes with carbs, though.

On another note, I think BMW has a bit to go on their FI. I just got the new GSX-R1000. The FI is as good as it gets. Ride one. You'll see what I'm talking about. Seemless, not a glitch.

BMW??

[daveel]

I've got a carbed KLR that I take way out in the sticks in eastern Oregon and camp by myself. When I get up in the morning I don't even think about it not starting, if it doesn't, I know I've got a fighting chance to get it running. When I take my S out in the sticks, there is always that moment of angst as I turn the key and hope I hear the fuel pump pressurize. If it doesn't, and I don't have cell coverage, start walking. Call me a luddite if you must!

[acidburn]

Get a satelite phone it takes care of that moment.

[tomn]

Acid: this is of course S forum so my concern on FI w/ or w/o sat phone is OT. however the grounded concern of riding bike and some sort of self sufficiency do run counter to FI shade tree repairability. Last week I was in Baja, where sat phone would surely work but even then any help might have been days away even if I had managed spanish. I solely depended on my backpacking and ultra distance running (up to 100 miles over mountains) yet was rather nervous since a slow spill could just get me or the pressure regulator.
I am not concerned when on R12S on pavement in the states, whereas I am when on my 650 out on a desert (only 4 weeks off show room, my 650 did not start one cold desert AM, I even heated the battery in a hot spring, but still no go, was luck to have a 4 wheeler come by and gave me a jump).
So all these tech have own strength.
I should just lhave a LOL on this thread and drop it but somehow I can't.

[1100s nut]

I understand from a good source that bmw(auto) has solinoid activated valve system, not mass produced yet but working that way. Thats going to be cool, change the valve mapping to a full race cam on the weekends and normal cam mon-fri. commuting to work, no more chains and cams and valve adj. Also from the same source, honda has a ultra high compression gas engine, very efficient but won`t run at low RPM`s and won`t run at high RPM`s sounds like they have some work to do there.

Regards,
Lane