Carbs on 1100's... DIY fantasy??

[uncle dick]

Just ordered the splitter box and twin cables to mod my '96. A little Christmas holiday project

 

[dancata]

I say that the splitter box is a poor design compared to the single cable actuation.

Some 1150's that I have ridden had a very hard to twist handlebar and my '95 RT throttle snaps back instantly

Dan.

 

[Wrigsby1]

Just ordered the splitter box and twin cables to mod my '96. A little Christmas holiday project

I was going to do the same as i blamed some of the changing cold/hot running on the orig cable but have been surprised how good i have set it up. I cleaned all around the cable pivot on the TB's as well as internally. Also the rattly noise from my RH TB pin was lateral play rather than wear.

 

[uncle dick]

I got mine pretty good on one cable but when the vac gauges are plugged in you can see how the rh pot lags when you open up and leads when you shut off. Anyone can see that there's no way it'll ever be any different. The 1150's I've tried have been no harder than my current setup and new cables are always a treat.

Should be a larf

Dick

 

[Hay Ewe]

have been interested in carbies for some time, but that is all. What I think would benefit most would be runnign two single cables from the twist grip, one for each TB.

any info on this? Thoughts Pro's / Cons?

What happens when putting carbies on? keep the same throttle cables?

I think I have seen some thing similar either on UKGSER or ADVRIDER

thanks

Hay Ewe

 

[Wrigsby1]

have been interested in carbies for some time, but that is all. What I think would benefit most would be runnign two single cables from the twist grip, one for each TB.

any info on this? Thoughts Pro's / Cons?

What happens when putting carbies on? keep the same throttle cables?

I think I have seen some thing similar either on UKGSER or ADVRIDER

thanks

Hay Ewe

Kerrching...

http://www.ukgser.com/forums/showthread.php?t=236298&highlight=carbs+oilhead

also Kenny had this done on his latest 11GS and posted a good thread...

 

[D6]

I say that the splitter box is a poor design compared to the single cable actuation.

Some 1150's that I have ridden had a very hard to twist handlebar and my '95 RT throttle snaps back instantly

Dan.

they havnt been set right/oiled then

 

[peter.james357]

carbs

I did the full carb conversion due to a corroded wiring loom and multiple break downs.SED can do all the work for you but are very helpful if you want to do the work yourself. The bike now goes like stink and was well worth the money.The bike is transformed from rather ponderous to a proper motorbike.In retrospect it is as pricey to renovate a pair of Bings as it is to buy a pair of Mikunis, though I imagine the performance will be even better. I tried to contact the Del Orto importer but they didnt bother to reply to any of my e mails.

 

[Wrigsby1]

I bought a 2nd hand Dellorto for a bit of sizing up and they are obviously a well known alternative on the airheads.

Bings are used 'cos they fit easily according to Steve S ("oilheads originally designed for them"...) and the folk that have had the conversion done. CV's seem to be better for low to mid torque and there was a bit of a run on eBay Bing prices after the articles hit the forum

Some of the alternatives are prohibitively expensive such as keihin FCR's etc.

I set up my TB's far tighter and sort of lost interest but the idea is still possible....

 

[uncle dick]

Just been out for a blast with the new 'twin cable' setup fitted. Installation actually quite simple with the original throttle bodies. Slight mods required as follows:

The choke cable adjustment is at the handlebar end on the new set up. Had to tweak the hand-shield thingy with a dremel to allow the new adjuster to sit properly. 10 minutes work.

The new throttle cable is longer so is routed differently - easy enough.

I think the later bikes have a compartment in the bottom of the battery tray for the splitter box to slot into. Mine seemed to sit quite happily and I wedged a piece of foam underneath it to stop any rattles.

The right hand cable inner seemed a tad short so I had to put a thin (1mm?) spacer in the adjuster ferrule where the outer sits at the throttle body end. Without this, the adjuster would have been right on the last thread to balance up. My bike has done 92k so this might well be different on something with less miles. BTW, to make the spacer, I just cut the hard plastic ferrule off the end of the old cable outer and put a slot in it to pass over the cable inner.

Absolute doddle to set up and balance and bike runs smoother than ever

If anyone wants any more info on this mod, just let me know if you need part numbers / pics etc.

Dick

 

[Kenny]

Looks nicer as well

Airhead on steroids

 

[dancata]

@Kenny,

What's the point on fitting carbs on an injection bike? You still need the HES for firing the plugs and I doubt that it will consume less gas on carbs than on the OEM injection.

Dan.

 

[Wrigsby1]

@Kenny,

What's the point on fitting carbs on an injection bike? You still need the HES for firing the plugs and I doubt that it will consume less gas on carbs than on the OEM injection.

Dan.

I think the argument is if you read the orig article by SED in the BMW Owners mag is that the R1100 series was originally developed with carbs and then fuel injection was used in late development and production. It has to be remembered that BM up until that point had used Bing's for their twins and that 1992/93 was a big changeover period for fuel preperation and emissions in Europe.

With that in mind the argument is that Bing CV 40mm carbs fit straight in and with the use of a seperate ignition system then the bike can work better in the realistic user range of 1100's, the low to mid range.

It has to be remembered that on 11's their were possibly some inherent slow running glitches that could have not been tuned out of the bikes from the factory. Added to the fact that the twin Motronic injection was at an early stage meant that that could be seen as a probs by some riders. Also the 5 speed gearbox didn't seem to accurately match the useable rev range and you had to change gear more than necessary.

BM's also take a long time to run in and can be more hesitant and glitchy in running when "tight" so they had some bad press when new for some of these factors.

According to Steve Scriminger of SED, carbs were there on early pre production pics and he is an expert with BM twins so he would spot this easily. Also when the build the R900 (or was it 8?) PD bike they used Bing's probably for their ease of service and the lack of bulky electronics.

All good fun and some people either never have or never percieve running issues with their 11's and some people still have issues. It is an issue that has been seen on many early fuel injected vehicles of all types and is still there on some.

 

[motobiker]

.All good fun and some people either never have or never percieve running issues with their 11's and some people still have issues. It is an issue that has been seen on many early fuel injected vehicles of all types and is still there on some.

Anyone who still has issues with the engine on a now 11-18yr old 1100 needs to use a different mechanic. Or put their own ego on hold and seek advice from someone who knows what they're doing.

 

[argos]

carbs and an aftermarket ignition system or an awful lot of wiring which will have gone brittle by now,2 relays to fail,a fuel pump to fail,o2 sensor which fails,pressurised fuel lines that split,internal fuel line clips that can and do come off,a throttle position sensor that wears out,doesnt like water and is mounted right were your boot catches it and they break easily,an oil temperature switch to go wrong,an air temperature switch to go wrong and did I mention the metres of not very accesible wiring?Without even considering the vast improvement in real world "driveability" that the right carbs will deliver for me its going to be carbs in the future.Love the bike,hate the fuel injection.It goes wrong more and more as the bikes get older,time to rejuvenate with some secondhand FCRs.Look on e bay they are not as expensive as you would think,buy a broadband sensor AFM and plug it straaight into the lambda aperture and jet it yourself. ps sell the motonic,the halls,the tps,the throttle bodies,the injectors,fuel pump,both temp sensors and you are not looking at a lot o expense

 

[roddy]

.....sell .......the halls,........

?

so whats going to fire the sparks ? if no hall sensors ?

 

[Wrigsby1]

Anyone who still has issues with the engine on a now 11-18yr old 1100 needs to use a different mechanic. Or put their own ego on hold and seek advice from someone who knows what they're doing.

I think we have been here before.... You seem to have a very good bike and good luck to you... It is not always the case and unless you have had another bike which has not been running quite right, you will not know what issues this can cause.

People like Steptoe and a few others seem to know by experience and expertise, how to set up motronic boxers very well, and their advice over the years has helped many people. There are also many dealers and mechanics who do not know how to set them up and just do the basic service work which is not in any shape or form, the same thing. My comment is "I once worked for a dealer and now do all my own service work..."

There is a lot of shite talked about bikes but the general debate about suspect running is not always this. I have learnt a great deal about my GS's and K's over the years and this is not exhaustive by any means but helps me to get the best out of my bike. We only use this forum to help each other if we can and I doubt that much of it is to do with massaging ego's. Also people can be quick to diss advice without knowing the whys or wherefores.

Also some of us like to try different things and are free to do it if we want.

Ta

 

[argos]

even when its set up correctly its limited by the maps in the motronic.It is designed to pass emission regulations,I suspect thats why they added the stick coils and second plugs to clean up,more to go wrong.My bike runs well relatively speaking but not as well as it could its still way too lean.Look at all the people fitting techlusions,power commanders etc.I dont need any more performance but if you fit carbs I would be willing to bet that pound for pound its the cheapest way to increase torque across the whole rev range.

 

[argos]

Roddy,aftermarket ignition £250,and with wiring that withstands engine temperatures out of the box unlike the standard halls.By the way did I mention TBs that are shockingly designed and guaranteed to wear out very quickly?Feeling better now

 

[roddy]

Roddy,aftermarket ignition £250,and with wiring that withstands engine temperatures out of the box......

but where would the new ignition pick up the timing feed to fire the sparks, I thought this was one of the functions of the halls ?

...Feeling better now

Didn't realise I was unwell, but thanks for the concern