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

Wrigsby1

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Well team 1100, with all recent chat about Bings etc on an 11 instead of the injectors I thought I would see about an info pow wow...

I like my 1100GS and don’t want to change for an 1150 (ridden many and like them) as I have my 11 to fit me and don’t want to start again. The big issue on an 11 can be the slow speed running especially on/off throttle. It is the only thing that is a bit of a pisser.

So... with recent stuff about carb fitting I want to scrounge info from the knowledgable about fitting carbs without going directly down the SED route. SED rebuilt my gearbox which is great but I can’t and don’t want for money and geographical reasons, to go to Lincs for the full works (yet!!).

Sooo.....

I want some to gather info about the possibility of a basic fit. I want to see if it is sensible and if you can get a reasonable setup in stages rather than go the whole hog straight away.Question time!

- How many people apart from Thunder and Kenny have had this done?

- How many have had a go themselves? Bowser seems to be someone who has been down this route.

- Bowser mentioned a “work around” of using the Motronic for ignition purposes and is this an OK short term method?

- What other ignition systems are available and where do you get ‘em?

- I have a plastic tank, is this a complete no go? Is it metal only and how does Steve S do this? Obviously ADV tanks are good due to the balance pipes and the easy ability to gravity feed.

- There are plenty of 40mm CV Bings fitted over the years to Airheads. Are they all compatible or is there only certain models that work and fit straight in?

- Are they a bitch to rejet or is it more brain in gear tinkering?

- Any obvious known dangers to the engine?

- Anyone tried Dellorto’s or Mikunis?

So there you go.... a little starter! This is mainly for 1100 owners who have been sitting there thinking about this since the recent airing of Thunder and Kenny’s stories. Some things like depressurised airboxes/cables can be worked out OK.

Being a million miles from a dyno it would be “self tested”. A fair amount of “tuning” is having a good feel for riding bikes and having a good diagnostic ability for thinking it through anyway so I am willing to get it “ballpark” ready.

Hopefully this will raise a debate for this mod and it may get somewhere Here’s hoping...:D
 
Wrigsby1 said:
Well team 1100, with all recent chat about Bings etc on an 11 instead of the injectors I thought I would see about an info pow wow...

I like my 1100GS and don’t want to change for an 1150 (ridden many and like them) as I have my 11 to fit me and don’t want to start again. The big issue on an 11 can be the slow speed running especially on/off throttle. It is the only thing that is a bit of a pisser.

So... with recent stuff about carb fitting I want to scrounge info from the knowledgable about fitting carbs without going directly down the SED route. SED rebuilt my gearbox which is great but I can’t and don’t want for money and geographical reasons, to go to Lincs for the full works (yet!!).

Sooo.....

I want some to gather info about the possibility of a basic fit. I want to see if it is sensible and if you can get a reasonable setup in stages rather than go the whole hog straight away.Question time!

- How many people apart from Thunder and Kenny have had this done?

- How many have had a go themselves? Bowser seems to be someone who has been down this route.

- Bowser mentioned a “work around” of using the Motronic for ignition purposes and is this an OK short term method?

- What other ignition systems are available and where do you get ‘em?

- I have a plastic tank, is this a complete no go? Is it metal only and how does Steve S do this? Obviously ADV tanks are good due to the balance pipes and the easy ability to gravity feed.

- There are plenty of 40mm CV Bings fitted over the years to Airheads. Are they all compatible or is there only certain models that work and fit straight in?

- Are they a bitch to rejet or is it more brain in gear tinkering?

- Any obvious known dangers to the engine?

- Anyone tried Dellorto’s or Mikunis?

So there you go.... a little starter! This is mainly for 1100 owners who have been sitting there thinking about this since the recent airing of Thunder and Kenny’s stories. Some things like depressurised airboxes/cables can be worked out OK.

Being a million miles from a dyno it would be “self tested”. A fair amount of “tuning” is having a good feel for riding bikes and having a good diagnostic ability for thinking it through anyway so I am willing to get it “ballpark” ready.

Hopefully this will raise a debate for this mod and it may get somewhere Here’s hoping...:D
Click to expand...


nope I did use the motronic for a while but I actualy got an ignition box from Scriminger, I used bings becuse I had them not because they are any good, I was speaking with a guy in Holland and he had fitted a pair of Mikuni flat slide carbs for a harley and his setup worked very well
 
I'm quite interested in this also. If I had the money and a second bike, I'd send the GS off to get done. Sadly I have neither......
 
Schtum said:
The closest one is actually c. 250 miles from Lerwick -

Highland Motorcycle Dynos
Davidston
CROMARTY
SCOTLAND
IV11 8XD
Click to expand...

Million miles and one 14hr ferry journey as is all parts of the "World":D Cheers for the info, I will check it out and see what they do and what they have got:thumb
 
bowser said:
nope I did use the motronic for a while but I actualy got an ignition box from Scriminger, I used bings becuse I had them not because they are any good, I was speaking with a guy in Holland and he had fitted a pair of Mikuni flat slide carbs for a harley and his setup worked very well
Click to expand...

Cheers Bowser, did you have to fiddle with jetting much or was it fairly common sense?

There seems to be some suitable 40mm alternatives from Mikuni and Dellorto but the Bings "fit straight on" it seems from the info.

Stages of tune is good as you can space the costs and have a think for yourself...:eek:
 
Wrigsby1 said:
Million miles and one 14hr ferry journey as is all parts of the "World":D Cheers for the info, I will check it out and see what they do and what they have got:thumb
Click to expand...

At least you've to RoRo these days, unlike the old St Clair where the only vehicle that were carried had to be winched on board.
 
Wrigsby1 said:
Cheers Bowser, did you have to fiddle with jetting much or was it fairly common sense?

There seems to be some suitable 40mm alternatives from Mikuni and Dellorto but the Bings "fit straight on" it seems from the info.

Stages of tune is good as you can space the costs and have a think for yourself...:eek:
Click to expand...

The 40mm bings fit straight on there is a very slight gap and I use some "speed Tape" (alli gaffer tape) and it was a snug fit, I upjetted them and spoke with scimminger re what sizes to try etc, the ignition unit was just a straight bolt one swap.

I eventualy took mine off as I had problems with the carbs I had in that they were old and I had problems with the float needle shutting off the supply as the carbs were worn.
I would have either tried the replacment float system or a new set and will when money allows.
To be honest I did like the dutch set up with the twin Mikuni HSR 40 or 42s, these are the standard ones used on harleys the only problem is that as more and more bikes go to FI (all harleys now are) there are less and less available in the dealers or second hand, and they are a bit pricy new I think in the region 300-400 each. I think the reason that bings are used is that they are redily available, cheap and fairly simple they are not however the best carbs in the world.

The cable set up was suprisingly easy to sort out, I used the plastic section at the top of the standard R1100GS cable and fitted it into the top section of an R100 cable then used the standard bmw splitter and the two lower section into the carb, same thing with the choke cable the standard R100 cables fitted right into the choke lever on the bars (I beleive it is exactly the same part).

With the fuel supply I disconnected the fuel pump and used a gravity fed system, on reflection I think that a low pressue pump would also work.
When I put the carbs back on my intention is to use the TT tank and the take off from the front lobes of the tank with a t piece so I have a balance pipe and then a single fuel supply line to each carb with inline fuel filter which will tidy up the plumping qutie a bit, and in addition frees up about an extra couple of liters in the tank.

The only issues I had were over pressurisation of the air box giving problems with the air flow through the carbs, what I did was to use a hole cutter and on the air intake on the bit that faces the frame I drilled a series of holes about the size of a 10 pence piece, and that sorted the problem.

With the jetting when I first started it was running out of steam around 6500 rpm due to not enough fuel at the top end, that was cured by going up a jet and moving the circlip on the needle.

To be honest there are a number of different carbs that could be made to fit, I would think the best thing is to measure the diamater of the flanges and see which ones are closest to the ones on the Gs1100/1150. If I had the money I would use either an HSR 42 if it fits or an Edlebrock the edlebrock is nice as it doesnt have and accel pump and is self mixture adjusting for altitude its also very simple to set up.

Overall I think the bike was much better for the set up, pick up at low speed was better, in and out of town traffic it was a totaly different bike, fuel consumption was about the same, acceleration was probably about the same but felt cleaner and there was no surging, top end suffered until I sorted out the jetting and after that was again about the same. For me it just felt nicer to ride, and smother. One bonus is that there are two hall sensors one to fire fuel and one to fire ignition, with the carb set up you only need one so if it fails you just swap the wires over and its fixed so you have a built in spare. I believe that there is someone who has gone the whole hog and replaced the ignition with points etc but that was way more effort that I was going to make and I didnt see any advantage with it. When I did my conversion I actualy left all the parts in place on the bike.
 
Bowser, I thank you for your thorough answer:bow

Thanks for all the detail from someone who has given it a go... All "us" 11 riders like to hear the slow speed running improvement bit as it's the only major bit that spoils the 11. Also the torque curve on Thunders dyno graph that is so good. No dip in the middle. There are plenty of dyno graphs for "chipped" bikes (including mine) and the dip in the middle was still there.

Thanks again:thumb2
 
Wrigsby1 said:
All "us" 11 riders like to hear the slow speed running improvement bit as it's the only major bit that spoils the 11.
Click to expand...


Hey Fella... don't include me in that rather sweeping statement. I simply don't see any problem with my bike at slow speed... it just potters along.
 
motobiker said:
Hey Fella... don't include me in that rather sweeping statement. I simply don't see any problem with my bike at slow speed... it just potters along.
Click to expand...

Mine stumbles like it's running out of petrol. Nearly a deathtrap taking a very slow S bend in first gear.
 
motobiker said:
Hey Fella... don't include me in that rather sweeping statement. I simply don't see any problem with my bike at slow speed... it just potters along.
Click to expand...

Correction... "Some" of "us" 1100 riders!:augie

Some do some don't, with the 11's it's very hit and miss. I used to sell BMW's and before that was an instructor, before that a courier, etc, etc yawn:augie

I have done plenty of miles at slow speeds, traffic splitting etc and BM 11's can make this a pain. I have tried all the usual tricks and setting and the only one that worked on 2 of my 3 GS's was having it rich with the ccp out.

I was given an 1150 when my 11 was in for a service back in 99 and the slow work as an instructor was transformed. The two best 11's i have ridden was a high mile 94GS and a low mile 99RT. No great correllation!

If you have a good one guard it with your life:D Mechanic/engineers like Steptoe have a good reputation for bringing the best out of them but when i worked for a dealer it was "what the machine says" and f all else.

I have watched customers being told of "character" when it obviously wasn't and made myself unpopular to get bikes set up better. My 2nd GS was dealer serviced for a bit and it never came back running the same twice.

A good test is to ride a continuous u turn virtually on the lock with a little amount of clutch slip if necessary. If it starts to lurch and fart it's like mine. Or ride at walking pace on very little throttle...

I like 11's and 1150's have their own little probs to sort:augie

AND I have had my gearbox fixed:D
 
tps on the fcr? that would cut the cost as no need to buy an after market ignition,just a thought...
 
Aha, this thread is back...:D

Aftet getting pissy with my 11Gs's running i totally cleaned out the TB's, quadruple checked the settings and balance, and now it runs the best it ever has and better than the last 2 11GS's i have had and also a load of 11's I rode while working for a dealer. Also fitted a cheap chip to boost the low/mid fuelling slightly with great results:thumb

So I guess the carb mod is on the back burner at the mo.....:augie
 
John Armstrong said:
Is that a surge cure or some other reason?

And you just know what the next question will be ;)
Click to expand...

I have a Remus road legal and a K&N fitted. The Remus is a bit more open but still not deafening and it lets the bike rev a bit more. This also probably weakens the mixture slightly and makes the bike a bit "yawny" or elastic throttle in the mid range. To be honest many std 11/1150 boxers can feel a bit like this especially if low and/or careful miles. The chip was advertised with some fantasy hp promise but it would be richening the mix slightly.

Bought on US eBay Motors from "XG Motorsports" for about £25 tops. I think they are probably clones of some other tuning shop:augie so were worth a punt. Previously had a Superchip on a previous 11GS with the same set up and it cost approx £250 for chip and dyno set up in 2001. As i saw on the day the chip bit isn't exactly rocket science but the set up is slightly more involved. I also found that the optimum dyno set up is not always the optimum road/seat of arse set up.

If you know what to do fitting takes less than an hour and this chip on my bike has made it far more lively in the important 2-5 k range and pulls smoothly through the range.

The caveat is always "my bike, my set up etc" and many 11's are different to ride and riders want different things. Also you mess at your own risk...:augie

The biggest thing to get rid of any snatchiness and kangaroo throttle action at the low end is to set the bike up meticulously! I found the cleaning of the TB's to be important on my bike.

PS The chip came with no instructions and the pins needed "adjusting" so it's not for the novice. I have 2 std chips in the garage just in case:D
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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