fuel injection vs carbs

I was intrigued by a comment about avoiding bikes with FI in the interests
of reliability. (It's always possible I misinterpreted the comments of
course).

It seems to me that in cars at least, the two biggest improvements in car
reliability have come aout thanks to electronic ignition and fuel
injection. Does this not apply to bikes or are there some very poor FI
systems out there?

Tim

 

september.org:

This is your post & Hog's reply

Things without full fairings then. Parallel/flat twins ideally, or singles.
Without EFI.
</q>

Note the context. He was talking about ease of diy servicing.

Bike EFI systems are pretty good nowadays and can be tinkered with by those
with the right software on their laptops.

Older EFI systems such as the Bosch job on my R-GS are piss easy to
maintain. Easier than the earlier versions of the bike with carbs I reckon.
Although, I'm too lazy to do my servicing and GAMI. I've watched him do the
tweaking and it takes a few minutes with dual pressure gauges.

 

On the SV forum there's one particular poster who encourages newbies to
buy the older curvy model because they have reliable carbs not fancy
and potentially expensively troublesome FI. Chris is a talented young
mechanic who knows his way round an SV blindfold and gets all manner of
tech questions thrown at him, which he answers with some bloody good
advice... except for that one thing.

A little while ago, just after he'd recommended one of those ultra
reliable carb models to someone, I pointed out to him that all of his
tech queries relating to bad fuelling, sticky chokes, knackered
throttle linkages etc came from carb model owners; no-one with an FI
bike had ever reported a problem. The earlier carb model was made from
1999 to 2002 and probably account for less than 25% of the bikes on the
forum, the FI bikes have been around for 8 years now and the FI is the
best bit about them - everything else fails or falls off, but never the
FI system.

Another thing I pointed out was, if an FI system does ever fail the
used parts to repair will cost pennies because the supply far outstrips
demand - no bugger ever needs them. You can't buy good used SV carbs
anywhere nowadays.

--
Lozzo
Versys 650 Inter-Continental Hyperbolistic Missile , CBR600F-W racebike
in the making, TS250C, RD400F (somewhere)
BMW E46 318iSE (it's a car, not one of those 2-wheeled pieces of shite
they churn out)

 

There is a reason carbs are going they way of the dinosaur. They are
shit. : )

There is a guy on aus.cars at the moment saying how great they are
because you can fix them yourself. He seems to miss the point that with
fuel injection you never need to fix it all.

Fraser

 

Never?
How many older FI cars have problems with tickover speed and starting?
How many Vauxhalls and French cars need replacement ECUs?

Do injectors wear? I don't think any car FI system can adjust fuelling
to individual injectors so the mixture could vary between cylinders.
I don't know if that is a problem.

 

Oooh... Take the idle valve off, fill it with carb cleaner, and give it a
shake...

Hmm. What was the name of that solvent again?

Wear and get clagged with muck from fuel, yes. But they cost me £50 to
have a set of four fully ultrasonically cleaned and the wearing parts
replaced a couple of years ago.

 

So that's another vote for 'FI never needs fixing'.

 

Eiron wibbled forthrightly:

Okay, it's probably wrong to say you never need to fix them. However
you need to fix them a damn sight less than carbs.

 

....after somewhere north of 200k miles...

 

Fewer, FFS!

 

Thanks to Wessie for clarifying what I said. In the reliability and
functionality stakes I'll take EFI every time but if it goes wrong I don't
have AFC how to intervene.
A single carb is piss easy to maintain OTOH.

Dual carbs should be easy too but on some bikes are a right caaant to get
at. Airhead carbs, being large simple CV's with open access are a doddle
and TBF if you service them every 5 years or so they never miss a beat.

I know Loz doesn't agree but I think a late Airhead with two simple mods is
the most reliable and easy to maintain bike you can run.

 

Does Slic add carbs to any of the modern race bikes? I doubt it somehow.
I don't know a damn thing about it, which bothers me, but I know there are
some amazing high flying custom EFI systems out there. With a laptop and a
Dyno (and a programmed brain) I expect the results are pretty amazing.

 

Engine wise, maybe. But what about when the starter motor or clutch
need replacing?

 

Every bike needs servicing.
Starter motors? what, once every 100k miles. At 50 take it out and service
the mechanism. It's a doddle to get at.
Clutch? again 100k unless you are cack handed and frankly it's real quick &
easy, when you know how and you have a little customized spanners and a
centering tool.

Almost all the (late) Airhead failures are down to a lack of servicing.
Starters, clutches, carbs and valves. It's so fucking easy to work on there
is no excuse. There is a reason you can't find used 1000cc engines, people
snap them up for light aeroplanes, which says loads.

The only two GAMI jobs are:
replacing mains, which is down to lack of oil changes or low oil or wrong
oil
gearbox rebuilds, for same reasons

Rebuilding the gearbox is actually a doddle but you have to shim the end
float just right.

 

A well tuned FI system is thew way forward end of. However there are
still some dodgy bike systems out there still. Well when I say some, I
mean the FI on the 990 KTM Adventure's from 2006 - 2008 (haven't
ridden a later one - apparently they are "better" but still not
great). My '06 Adv was a nightmare "just off closed throttle" and off
road was a liability. Got to the point that I traded it for a 950
SuperEnduro because a) I always fancied one, and b) it had carbs which
I've adjusted to suit the bike / my riding[1]. The Adv forums are
always one about trying to tune the FI - if they get it right (and I
mean Tuono / '05 Gixr1000 right) I'd have another, but not until then.

cheers

SS

[1] still "snap, crackles and pops" on the over run, but I quite like
it......[2]
[2] I'm sure a GOOD FI system would be better but it's not available
on them

 

Hmm, a friend has offered to sell me his old R100RT (in need of some
restoration work). Shoud I bite?

Tim

 

Depends on what needs doing. A lot of BMW spares are surprisingly
cheap. But c(for example) replacing a clutch is a bugger as the bike
is basically built around it, and gearbox work can be very expensive.

 

Well as TOG says a) depends on what needs doing, b) how much he wants
for it , and c) are you handy with the spanners to do it yourself, or
will you need to pay someone?

Also is that really the sort of first bike you want? If it's dead
cheap and doesn't need much doing then it's cheap to drop the few
times you might over the first year or so, where as a "new and shiney"
will break your heart if/when you drop it.

cheers

SS

 

Bit heavy and expensive to repair for a first big bike, I'd say.

 

If it's a late Mono then it is worth considering. Earlier models are for
Collectors.
Spot earlier models by twin shocks