Can someone please explain to me the pro's and con's of running an engine on carbs vs injection, aiming the answer at someone who isn't hugely mechanical.

As far as I understand the carbs is "easier" to setup but are there other advantages?

What engine do you have in mind?

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Originally posted by mookaloid
What engine do you have in mind?

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Sorry not sure what the best advice is for an R1 - I'm sure there are plenty of BEC users who will have an opinion though

Cheers

Mark

My carb'd R1 goes like stink and carburates beautifully on the TTS kit!

Plus, I've got a set of Keihin CR41 flatslides to throw at it once I get bored.....

Comparing the two R1's, I don't think you'd notice much of a difference in the real world, so it's probably come down to which package you could get for the best money! I don't think that one is more difficult to install than the other - just different!

Fuel injection is generally better, that's why major companies all use it now. For a kit car, you can tune a FI engine using an aftermarket ECU such as mega jolt for a car engine or power commander for a bike engine. You will need a computer with the apropriate software to programme these. I am told it is not too dificult. The results can be excelent beacuse you can alter the ignition timing at 500 RPM intervals and alter it at every engine speed according to load or throttle position. try doing that with a carb!

carbs don't need expensive electronics or computers. Screwdrivers do the job, except that they can't do it as well and you have to have a general overall setting of the carb screws.

Carbs are cheap and simple where as fuel injection is good but expensive.

I'll probably stand corrected on this but I believe the only reason for going injection in the first place was to achieve ever tightening emissions. As there are less moving parts; in theory it should be more reliable. There may also be a bias towards the injection for more mpg, but I doubt this is at the top of your itinery!

I am currently in the process of upgrading to FI (Yam R1 2001 carb to 2003 FI).

As far as absolute power is concerned I dont believe there is much in it. Power delivery is something else though. Although not impossible with carbs it is much simpler to use FI mapping to clean up flat spots. Flatslides are a little special but at £500+ s/h but move the bar up a bit.

The smoothness of the FI power delivery was one of the main reasons why I have chosen this route.

Just my 2p

[Edited on 7/9/05 by jimgiblett]

No contest injection is better for power, economy, ease of setting up.
But it's harder to do the wiring & more expensive.
I've recently finished putting webers on a RV8 including making my own manifolds. I wish I'd gone the injection route - something like the emerald system - the DIY tuning with a wideband 02 sensor gives you much better results in the end- plus the learning curve would have been more interesting & more pertinent to the 21st century!
Bob

Various schools of thought - that's what I like to see!

As far as carbs are concerned, there are massive variations.... Webers are 40 year-old technology, certainly compared to a set of Mikuni CV's off an R1 or a set of flatslides. Webers don't actually control the amount of fuel administered at part-throttle settings, whereas bike carbs do via a tapered needle sliding in and out of an emulsion tube. These needles can be tapered to suit (even having negative tapers if required!!!).

I know of a chap who has fitted a set of bike carbs (off an R1) onto his S2 Twincam Lotus 7 and has witnessed a marvellous improvement! It cost him around £250 in total (including manifolds and rolling road time to sort the jetting) and he's capped to bits!

So, my view is that injection is good and easier to set up (and get horribly and terminally wrong) for the average person, but a decent set of carbs are very tuneable if you have an understanding...

Ok, I will admit that I'm a bit old-skool and like to tweak with tools as opposed to plugging in a piece of electronics, and my flatslides are a gorgeous piece of kit, but considering that my R1 has never seen a rolling road and is fitted with a 4-2-1 exhaust to the Allbikes European championship sidecar design with a TTS R1-car jet kit (needles raised one notch from stock) and a Pipercross filter it goes beautifully, with no noticeable flatspots whatsoever!

[Edited on 7/9/05 by Coose]

being a bit of a computer geek, i was tempted to the FI route, simply for the easy customisability. plug in laptop, upload new fuel map and go.
this sounded great for changing the car. one 'wimpy' map with clean emmissions for SVA, an average power map with decent(ish) fuel economy for pootling around, and a balls-out power map for track use.

whereas i know nothing about carbs, and i'd have to get it rolling road tuned, and i'd be sticking with that one setup for everything. (until i got the hang of fiddling with the screws)

there isnt a great deal in it if you only consider engine price, but dont forget the power commander which adds another 150-200 quid on top.

alas, i went for carbs in the end as there was an engine going quite cheap at the time and im now on a fairly tight budget.