Carburetters

bulldog · 07-17-2001, 05:49 PM

Just bought an R1100S. Very sexy bike to look at, wonderful design features and , well, different. However much as I love it lets face it guys the fuel injection is pure *****. Any japanese bike maker (love em or hate em (I am neutral before you start..

)) wouldn't last five minutes producing an injection system as jerky at low revs. Very flaky. Does anyone know anything about getting carbs for the bike? I for one am seriously thinking about them. I've read about zeroing the TPS etc and WILL give it a try but I am dubious about its long lasting effects.

Rapt · 07-17-2001, 07:41 PM

Are you sure everything is adjusted properly? Mine isn't jerky at low revs...

And I only wish the carburetted Honda 600 I own ran as well as my S at low revs...

doberman · 07-18-2001, 12:44 AM

Just get em synched properly.
I did have problems, but not anymore.

------------------
Safe Riding

Bent

Spiralgalaxy5 · 07-18-2001, 04:24 AM

Near 'instant' throttle response + Low down grunt + fuel cut-off whilst twistgrip is closed = "jerky" to a lot of people when first confronted with the bike - give yourself some time to get used to it first

My guess is that carbs may solve a couple of 'problems' and introduce a dozen more!

Len · 07-18-2001, 05:00 AM

One extra point, is that unlike older BMW's the S is not realy a low rev bike. I find a gear lower than might be thought standard helps. I guess that does not help when you are in first, but stay off the higher gears until you are on the open road.

Len

roger albert · 07-18-2001, 07:11 AM

Dittos from this quarter. You may be out of adjustment and are probably not used to the FI yet, much less the S specifically. While the Bosch injection is certainly not up to the standards of Marelli or Sagem, its actually better than some of the early japanese efforts. Suzuki (normally not my fav Japanese Vendor) seems to have done a great job of late. If you'd had a chance to ride more injected Japanese bikes, you'd be singing a different tune. I will agree though, that for a company that has done FI over a decade now, BMW still has a lot to learn.

Still, except for surging (which careful tuning can minimize or negate in some cases) its not a bad system. It takes a while to adjust ones throttle technique to match an injector which isn't a sluggish carb. For that matter, when I bought my Mikuni carb'd, semi-flat-slide duc, it required more finesse than my old round slide bing'd bmws. That was actually a larger change.

Anyway, check your adjustment and practice a bit. I bet you become happier.

Good luck in any event.

later
roger

Chris Canning · 07-18-2001, 12:04 PM

If you check through the back threads on chips,you will some postings by Adrian W.He had his S chipped with a custom one.The company is called Superchips(in the UK) and you turn up with what ever combo you've got and they set it up to the optimum setting.I spoke to the company last year they quoted me around £250 sterling and that included the number of runs on the dyno it took to set it up.They leave the original chip in situ and cut into the wireing to fit their own

bulldog · 07-18-2001, 02:31 PM

Thanks for the responses and encouragment guys. I WILL persist with it. Done slides now about to embark on TPS setting....now where's me hammer and me DVM....?

fredman · 07-18-2001, 09:28 PM

Bulldog
Hammer & DVM? sounds like you should be working on a Harley!

trublue · 07-19-2001, 05:03 AM

While your at it, probably got 2 to many valves !, and you could probably hunt up a set of low mileage "earles forks' for her !.

Trust me Bulldog after spending big bucks in pursuit of horsepower out of my trusty R90/6 over the past few years, IMO the single biggest thing the S has going for it is injection and Engine management system . Great in standard form and still heeps of potential to go crazy .
Changing back to carbs is "chucking the baby out with the wash water" .Persevere mate.
Mick .
76-R90/6
2001-R11S.

bulldog · 07-21-2001, 05:08 PM

OK guys I put in Autolite plugs, set up the TBs and did the whole TPS setting thing and (fair enough I did have to use Vacuum gauges - Carb Stix on its way) I must say it is better but not completely gone. I appreciate what you say about instant throttle response and your right this can be a factor especially whilst coasting down a rough road surface so I take your point. I guess I'll just have to retune when me carbstix comes and see how it goes.