Carbs Vs. Fuel Injection?

[PBJ]

Pegscraper brought this up on another thread and I thought this would be a good discussion.

 

In 2010 it looks like there couls be a totally new redesign for the Venture. Speculation is that at its heart will be the new V-Max engine in some form of detune , probably with strong low and mid range. The V-max engine is Fuel Injected. The question is will it reall make the engine and bike more effecient or is carburetor technlogy still viable?

 

I used to work for Delphi where we delevoped the Efi for Harley. All indications so far are that the Harley engine start quicker with no warm up neccesary and that the engines actually run smoother and have better throttle response.

 

Plus new Fly-by-wire technology is all the rage F.I .is needed to go to that step. ? What do you think?

[GeorgeS]

Based on performance of 2 Automobiles I have owened, and one motorcycle that are equiped withe EFI, Its all Thumbs UP !!!

 

Much better performance, Much fewer Maintenance problems, Its all Win Win Win.

 

Now haveing said that, I'm not going to t sell the 89, just because it has Carbs !!

 

But any Bike I buy in the future, ( IF New ) will be fuel injected !!

[BoomerCPO]

The bike I owned previous to my current Venture had EFI and I loved it. Instant start-ups even in the frozen North here....and the throttle response was the best of all.Gas mileage was very good and consistent year round.

 

I for one will NOT miss the Carb's if they go away with Cassette players.

 

IF,and I use the term loosely, Yamaha upgrades the Venture by 2010 I will be taking a hard look at acquiring the 3rd Gen Venture for sure.

[CrazyHorse]

You can program EFI also which is nice with carbs your messing around with jets sizes trying to match them up etc. Plus in our carbs messing with a diaphrams, floats and the general BS you have to do with a carb you dont have to do with EFI. EFI is just alot more user friendly and more efficient you pretty much dont have to worry about them. Maybe some cleaner in the gas tank once in awhile. Otherwise pretty much zero maintenance. Why screw with carbs just more work instead of riding. (Unless you like to of course) Just my H.O.

[greg_in_london]

I certainly like the idea of fuel injection - and fuel management in general - but I'm not sure of many examples where the new injected model has been more economical. My commuting bike is an XTZ660 which does mid 50s to the gallon (UK) in a range of riding conditions including heavy traffic ~ slightly more on a long run. The new version XT660 apparently can't equal that. Why not ????

 

Why should I buy a new bike that will do the same speed, but use more petrol doing it ?

 

I've heard that the later BMW funduros can be pretty good on juice, though. It doesn't seem much of an explanation to say that these are first generation systems as they must have at least fifteen years' experience designing these systems by now.

[Trimster]

EFI would have been a god-send on this past 28 day road trip. The ethanol mix ran in the carb'd bike but the mileage is 25mpg at best. The newer HD, Wings and Beemers were having no real issues with the blended fuel. I am a firm believer that the ethanol idea is a bad one anyway... but it is hard to find fuel that does not have at least 10% in the mid states, we found.

 

Your mileage may vary... ours did

[Gearhead]

Well, EFI has certainly helped cars increase mileage in the last 20 years. They say a well-tuned carb will produce as much power, but not the mileage of EFI. That being said, my 91 3/4 ton Suburban gets 11-12 mpg from it's injected 350, while my old 77 3/4 ton Chevy pickup, carbureted, got, well, about the same. The Sub does weigh 1000 lb more. But I work with a guy that says his much newer 1/2 ton Suburban with a 5.3L gets close to 20 on the road.

 

I've toured with a guy on a 1100 BMW sport-touring bike with EFI. His mileage was mid-50's IIRC. Can't argue with that. And that was one fast bike, too.

 

I really like not working on carbs with my EFI cars. EFI problems are a pain, but rare. That alone is a wonderful thing.

 

One more benefit. Anyone wonder why the average car engine used to wear out around 100k miles and now that's more like 200k? One trusted motor machinist told me it's primarily EFI which accounts for that. Most wear occurs at startup, and the CHOKE on a carb greatly exacerbates that. Carbs need a choke because the cold piston and combustion chamber aren't condusive to atomizing the stream of liquid fuel from the carb, so it doesn't burn very well. The choke compensates by dumping great excesses of fuel in, increasing the AFR (air fuel ratio) from 14:1 to around 7:1. As the engine warms, the fuel atomizes better and the choke is no longer needed. Since injectors spray a more atomized form of fuel into the chamber, it burns much better even when cold and all the extra that's needed is a quick squirt from the cold-start injector. Anyway, when the choke is on, all that excess fuel washes down the cylinder walls of their oil, and over time that's 100k miles worth of wear on the engine.

 

Jeremy

[KiteSquid]

EFI for the 3rd gen RSV!!!!

 

The R&D money was already spent on the V-Max, so just a little tweaking to put it in the RSV so Yamaha has a better return on their investment.

 

I am looking forward to the 3rd Gen RSV.

 

When it is released, my 2nd gen will go up for sale, of course if they don't go too far from the current styling.

[hig4s]

Really I find the actual work needed to work on carbs not that big a deal, and not that hard. The big deal comes with multi cylinder engines saving on space and making it almost impossible to get the carbs off to work on them.

 

With a little tuning and practice carbs are very viable, but do suffer a bit on long trips with elevation changes, and fuel differences.

 

FI is much more forgiving as it automatically changes as necessary for elevation and fuel differences. It also reduces emissions and gets consistently better fuel mileage. But as the technology grows, EPA will continue to add regulations that will make it harder and more expensive to modify electronically controlled engines for those that enjoy working on their machines and like to modify them for performance.

 

For me FI would be better as I very seldom do anything to my carbs, and if I had FI I would never do anything to it.

 

No back when I dirt biked, I played with carbs all the time, and enjoyed it. But pulling a carb off a motocross bike to put in on the bench was usually only 4 or 5 screws and one cable, and there was room to get my whole hand in there to do it.

[5bikes]

Carbs are easy tuned with inexpensive tools. They are reliable if kept clean and used often. They can be tuned for performance or economy for almost nothing. But they can be a pain if gas/air is dirty and/or infrequently used.

 

Fuel injection requires much more expensive tuning equipment. It is more relaible. Can be left unused for weeks/months without maintenance. FI is expensive to repair and most systems can not be done by backyard mechanics.

 

Properly tuned carbs can get the same MPG as FI.

 

Aftermarket loud pipes usually screw up the the mixture. Most bikes go richer, have to be leaned. 4 bikes experience. I can tune carbs for aftermarket pipes but need special equipment to realign the mixture on FI.

 

It just depends on what you want or what you bought.

 

All my bikes get 46+ mpg to 75 mpg and all have carbs. Guess who gets a lot of tuning work?

Edited July 23, 2008 by 5bikes
Added more

[BuddyRich]

I had FI on 2 previous bikes and loved it. The only advantage I can see carbs having is that you can still push start a bike with a totally dead battery where as with FI if there's no electric theres no fuel so there's no way to push start. But I stopped push starting 800 lbs bike a while back anyway. Dang things are too heavy to push far. :rotf:

[ediddy]

If yamaha goes with FI I hope they don't have the heat problem the harleys have. To comply with EPA the 07 and 08 harleys are running so lean they will cook the passenger. The venture is already hot enough.

[Freebird]

I don't know WHEN we will see a new Venture and I don't know if it will be second gen style or first gen style but there is absolutely NO doubt in my mind that it will be FI when we see it.

[Gearhead]

All my bikes get 46+ mpg to 75 mpg and all have carbs. Guess who gets a lot of tuning work?

 

 

Hey 5bikes,

 

So what's your secret? Most of us here would LOVE to get that mileage from a Venture. I've never beaten 42, and that's on slow rides; it's usually averaging 37. Did you have to change stock jetting or is it simpler than that?

 

Jeremy

[Guest tx2sturgis]

FI is much more forgiving as it automatically changes as necessary for elevation and fuel differences. It also reduces emissions and gets consistently better fuel mileage. But as the technology grows, EPA will continue to add regulations that will make it harder and more expensive to modify electronically controlled engines for those that enjoy working on their machines and like to modify them for performance.

 

For me FI would be better as I very seldom do anything to my carbs, and if I had FI I would never do anything to it.

 

 

 

Maybe. Maybe not.

 

Some motorcycle FI systems use a closed loop, and a preset fuel map. So, if you make changes to the airflow (louder pipes?), you may have problems. Normally, it just means an add-on FI manager, or a reflash of the ECM.

 

 

[Guest tx2sturgis]

 

Aftermarket loud pipes usually screw up the the mixture. Most bikes go richer, have to be leaned. 4 bikes experience. I can tune carbs for aftermarket pipes but need special equipment to realign the mixture on FI.

 

 

Huh? Most carburetted bikes go LEANER when adding freeflowing exhaust and/or free flowing air cleaner, especially at lower altitudes. Thats why you had to richen the mixture by going up on jets, needles, or spacers.

[5bikes]

How to increase gas mileage and performance:

Carbs must be clean. Air filter clean. Take the cover of all 4 carbs, 1 at a time. Remove the diaphram and slide, remove the jet needle under the large screw. Replace the spacer under the circle clip with very small washers. Perhaps 2. You want the needle to be longer, projecting out the bottom of the slide another .010-.020".

Make sure the carbs are synched, so they are all pulling the same vacuum.

Drive a steady speed, use only regular gas.

[Gearhead]

Thanks, 5bikes, I'll give it a shot one of these days. The tuneup items I have covered, but never tried lowering the needles. Do you mean "thinner" washers to replace the stock spacer?

 

Jeremy

[CrazyHorse]

If yamaha goes with FI I hope they don't have the heat problem the harleys have. To comply with EPA the 07 and 08 harleys are running so lean they will cook the passenger. The venture is already hot enough.

 

 

Even with the oil cooler on them they run hot.

[Christo]

I am here at StarDays, was talking with the Star people from Yamaha, they know nothing of or about the 3rd gen of Venture, but there was consensus - the VMax de-tuned is highly unlikely for the Venture, what was said between 3 the different Star Corp types here is that the 1900 V Twin might be the new motor for the Venture. The VMax has too much $$ involved in the current new design and to detune it would not be cost efficient. So something to chew on.

[Freebird]

Christo,

Thanks for the report. It's fun to speculate about these things. One thing I can tell you for sure though after hearing these Yamaha "corporate" types yack at various events for about 10 years now is that their predictions are no better than any of ours. Yamaha keeps them so much in the dark that they are really better off not saying anything at all. Their comments about it being too expensive to detune the motor shows me even more that they don't know what they are talking about. It is VERY simple and cheap to detune an engine.

[BuddyRich]

Why detune it. Just put a bigger tire on the back and give us wheelie bars and were good to go.

[bobbyduck]

Instant start-ups even in the frozen North here....

 

What North? You mean South don't you?

 

[PBJ]

Christo,

Thanks for the report. It's fun to speculate about these things. One thing I can tell you for sure though after hearing these Yamaha "corporate" types yack at various events for about 10 years now is that their predictions are no better than any of ours. Yamaha keeps them so much in the dark that they are really better off not saying anything at all. Their comments about it being too expensive to detune the motor shows me even more that they don't know what they are talking about. It is VERY simple and cheap to detune an engine.

 

I wouldn't doubt if they'd be trying to throw off any early speculation because it would ruin new product intro. But the 1900 V twin seems unlikely (Though not impossible). Its the V4 engine that makes a Venture,a Venture . Otherwise they would have dropped the 1600 VTwin or one of the other engines in there along time ago. That would have been cheaper still if going cheap was a real answer.

 

Nope, I'm still going with a V4 detuned V-Max making around 100-120 bhp and 80-90 lb. ft. of torque

[BoomerCPO]

What North? You mean South don't you?

 

 

ROFL! Yes I concede that it is colder in your neck of the woods......but to me anytime the temp is lower than 50degrees I AM COLD!

 

Ride safe Bro...........Boomer