Exhaust Advantage?

[oilcan]

My 1100 currently has the stock exhaust fitted with a cat as it has the "Lambda" (?) sensor on the exhaust.

What advantage would I gain by swapping the exhaust of another stock one but without the Lambda sensor and no cat? What happens to the sensor and what adjustments would need to be done?

In fact, is there any great advantage to be gained as it was only a fleeting thought?

 

[Wrigsby1]

My understanding is the bike either needs a lambda or a CO pot as with UK bikes. You probably have a European import and it will probably have a different cat code plug than the mauve/brown UK ones (If it has one still...).

I don't think there is any advantage either way. You will find that Remus etc give you a lambda mounting point on their kit anyway.

 

[John Armstrong]

I've both a Remus S pipe and the Remus pipe with a box on it, and both have a hole for the lambada sensor. Blanked on my UK bike.

 

[motobiker]

My 1100 currently has the stock exhaust fitted with a cat as it has the "Lambda" (?) sensor on the exhaust.

What advantage would I gain by swapping the exhaust of another stock one but without the Lambda sensor and no cat? What happens to the sensor and what adjustments would need to be done?

In fact, is there any great advantage to be gained as it was only a fleeting thought?

Exactly what I have done to my bike which was a german import.. very originally. My bike was rather unusual in that it had BOTH a cat.. and a CO pot factory fitted.

When it was originally brought into the country with zero miles.. it was fully converted to UK spec.. apart from the exhaust.

When the exhaust was swapped.. I found a 'brand new - unused' one on Ebay for £20 (delivered) - removed the lamda cable.. unplugged it from the loom and the Motronic then defaulted to the CO Pot. you can quite easily retrofit a CO pot to the normal place under the seat.. on the RHS. the cable and connector will be there. waiting to accept it.

I did it.. because the CAT had died.. (bless it) fuelling was really bad. I had major sooting around the end of the can.. a full tank would struggle to acheive 120 miles.

Swapping cured all that. I now get the normal... 220+ miles to the tank. and have no CCP.

I have absolutely no intention of ever fitting an after market exhaust... why fix what isn't broken? I really like the looks of the Original. In my opinion moving from a fully stainless steel.. to an alloy system is a retrograde step. despite the weight saving. If I was concerned about weight.. I wouldn't be riding a GS.

 

[oilcan]

When the exhaust was swapped.. I found a 'brand new - unused' one on Ebay for £20 (delivered) - removed the lamda cable.. unplugged it from the loom and the Motronic then defaulted to the CO Pot. you can quite easily retrofit a CO pot to the normal place under the seat.. on the RHS. the cable and connector will be there. waiting to accept it.

I did it.. because the CAT had died.. (bless it) fuelling was really bad. I had major sooting around the end of the can.. a full tank would struggle to acheive 120 miles.

Swapping cured all that. I now get the normal... 220+ miles to the tank. and have no CCP.

Thanks for that, great help and good to know you too have changed over. What's a CO pot and it's purpose?

I'm assuming then (little knowledge of bikes) the connector into my current exhaust is the Lamda sesnsor for the cat, yes? Any by doing away with the cat the CO pot replaces the Lamda Sensor?

?

 

[motobiker]

Its used to adjust the mixture.. you will need a CO analyser and turn it.. the pot to achieve the correct amount of CO in the exhaust gases. I had this done at a garage. I forget what the correct % should be.. but, what I do know is that you only need do this once. I had this done almost 5 years ago.

 

[Wrigsby1]

CO pot sets CO at tickover. Without the CAT the bike runs "open loop" all the time rather than "open loop" on wider throttle position and "closed loop" on steady throttle/closed throttle.

Basically the difference is that without the Lambda the engine fuels by reading air temp in the airbox against engine temp and throttle position. The Lambda sensor analyses the exhaust gases and in "closed loop" it leans things off a little. It has a very slight lag in catching up so that is why there can be steady speed slight surging on Cat/lambda bikes.

That's what I remember anyway, hope I'm right as I never remember Cat/Lambda bikes being very "surgy" when I rode 'em.

 

[oilcan]

CO pot sets CO at tickover. Without the CAT the bike runs "open loop" all the time rather than "open loop" on wider throttle position and "closed loop" on steady throttle/closed throttle.

Basically the difference is that without the Lambda the engine fuels by reading air temp in the airbox against engine temp and throttle position. The Lambda sensor analyses the exhaust gases and in "closed loop" it leans things off a little. It has a very slight lag in catching up so that is why there can be steady speed slight surging on Cat/lambda bikes.

That's what I remember anyway, hope I'm right as I never remember Cat/Lambda bikes being very "surgy" when I rode 'em.

My bike does suffer with constant speed surging at around 3K rpm, I've wondered if that might be the cause.

Will the CO pot need to e set up and is it as easy as unplug the Lamda Sensor and plug in the CO pot?

 

[Wrigsby1]

The CO pot is a resistor potentiometer that works by richening or weakening the tickover fuelling as you turn it one way or the other. It adjusts clockwise for weaker and anticlockwise for richer. It is an endless pot so you can't just work it out on a 1-10 like a normal pot (1-11 for Spinal Tap fans).

You need to have a good CO meter at hand such as your friendly MOT station gas analyser. You get theengine good and hot and then run it on tickover while check the CO on the machine. It is supposed to be 1.5% +/- 0.5%. They are usually best at 1.5% or just above. The adjustment is sensitive and you need to check the reading after a quick rev each adjustment. It takes a few seconds to settle after each rev.

It fits under the offside rear part of the tail piece level with the rear seat. You will find a handy hole if you look in't guard.

 

[oilcan]

Ok thanks for the info so far.

Can I just clarify then,

1. disconnect Lamda sensor and remove old exhaust (disconnect lamda sensor from wiring loom also?)

2. fit new exhaust.

3. Plug in CO pot (where? into wiring loom?)

4. Run bike to hot and test CO output and adjust?

Is it really as simple as that as I'm no mechanic? If I do points 1 to 3 will the bike run with no lambda sensor and not being set up on the CO pot?

 

[Wrigsby1]

Ok thanks for the info so far.

Can I just clarify then,

1. disconnect Lamda sensor and remove old exhaust (disconnect lamda sensor from wiring loom also?)

2. fit new exhaust.

3. Plug in CO pot (where? into wiring loom?)

4. Run bike to hot and test CO output and adjust?

Is it really as simple as that as I'm no mechanic? If I do points 1 to 3 will the bike run with no lambda sensor and not being set up on the CO pot?

Ah, the clarity bit

You carry out all work at your own risk etc and if it doesn't work you should have kept your lambda

1-3 should be fine but it may be a bit rich or weak. If you have a multi meter you can check the resistance of the pot, it's range and set it somewhere in the middle for starters.

CO pots are really just for tickover fuelling and anything above 1750/2k should be OK. That is where the main "open loop" fuelling kicks in and you can feel this on the overrun on the road as it returns past these revs as the tickover fuelling kicks in.

You will know if it's a bit rich as the end can will look sooty pretty quickly.

It will need setting up eventually as 11's are sensitive to tickover setting, TPS setting, and throttle body balance for slow speed work.

Make sure it's clear in your head before going ahead as it sounds like the bike is pretty OK as it is. It does take a small amount of dialling back in.

Can't remember the exact location of the pot connector on the loom but its fairly obvious. I had mine off a bit ago to test the resistance as i though it had gone duff.

 

[motobiker]

The connection for the CO pot should be under the seat on the RHS.. towards the rear.

Problem is though.. I think you will find TWO. one is for the CO pot. the other is for.. I believe its something to do with emissions in california. How to differentiate between the two? I have no idea.

Of course.. your bike may only have one... and it could be either.

My advice is to take it to someone who knows what they're doing. who can do the job and then set the bike up correctly for you.

As and when you track down an original UK spec exhaust.. of course.

 

[MattW]

Interesting thread.
My tailpipe gets sooty - still get 200+ to a tank so I think the fuelling at higher revs is ok. I might pop to the local MOT station and see if I can take a look at the CO at tickover.

 

[motobiker]

Can't remember the exact location of the pot connector on the loom but its fairly obvious. I had mine off a bit ago to test the resistance as i though it had gone duff.

you are joking of course. you took it off and can't remember where it was!! what????



best get to the doctor chap.

 

[Wrigsby1]

you are joking of course. you took it off and can't remember where it was!! what????



best get to the doctor chap.

Ah... you see it was more than a month ago so is no longer important and I sort of remembered there was two and didn't want to be the bloke that told him the wrong one. Also I din't really think I needed to go out to the garage and take the seat off to have a look.

It is "under the seat attached to the loom". That is what is called hedging your bets and leaving some of the thinking to be done by the bloke doing the job...

I think the other connector is for the exasperationometer...

 

[motobiker]

Here they are in all their glory.. as you can see the one has the potentiometer attached... the other (for california) above. How to tell the difference between the two if No POT is attached. I for one have no idea at all. Also I have no idea why my bike had a pot in place despite it being a 'german market' bike with Lamda and Cat. All i can assume is that the bike.. being one of the last, was built with no clear end destination in mind... until the last minute. Or.. could be that all CAT equipped 1100s had a CO POT fitted... but the Motronic doesn't recognise it IF there is a Lamda connected to the loom too.

No need to take the seat off.. they're not under it. They sit in a little recess in the plastic (upper mudguard??). you can see a hole above. they reside there.. the hole is to allow any water to drain away.

 

[Comfy Old Boots]

I had an experience on my '99 r850r a few years ago. I was in andora and the bike kept dying. Turned out my bike with cat and co2 pot couldn't cope with altitudes. Is this to do with it being an open fueling loop or just one of the 'budget' parts of the r850r? Just wondering if I could fit a lambda to my bike (as has been suggested) and possibly cure it's altitude sickness? In other words, would it be a good idea to keep your lambda sensor?

 

[Wrigsby1]

Here they are in all their glory.. as you can see the one has the potentiometer attached... the other (for california) above. How to tell the difference between the two if No POT is attached. I for one have no idea at all. Also I have no idea why my bike had a pot in place despite it being a 'german market' bike with Lamda and Cat. All i can assume is that the bike.. being one of the last, was built with no clear end destination in mind... until the last minute. Or.. could be that all CAT equipped 1100s had a CO POT fitted... but the Motronic doesn't recognise it IF there is a Lamda connected to the loom too.

No need to take the seat off.. they're not under it. They sit in a little recess in the plastic (upper mudguard??). you can see a hole above. they reside there.. the hole is to allow any water to drain away.

Now you have reminded me where it was... well done I took the tool tray off (one bolt) and it was on a natty little bracket which lined it up with the hole for adjustment. The hole is actually for the screwdriver and yours is missing the bracket which bolts onto the free threaded hole in your pic.

Top drawer... an answer without needing me to get cold, blown away and take a pic ( I was riding today on commute... frosty this morn, gales tonight).

I imagine the Andorra thing might be to do with the open loop as it has no "self adjust" without the gas out Lambda.

 

[Comfy Old Boots]

Now you have reminded me where it was... well done I took the tool tray off (one bolt) and it was on a natty little bracket which lined it up with the hole for adjustment. The hole is actually for the screwdriver and yours is missing the bracket which bolts onto the free threaded hole in your pic.

Top drawer... an answer without needing me to get cold, blown away and take a pic ( I was riding today on commute... frosty this morn, gales tonight).

I imagine the Andorra thing might be to do with the open loop as it has no "self adjust" without the gas out Lambda.

Interesting. The co2 pot is a retrofit then.

Or is the co2 pot better able to fool the moronic for smoother local running?

The co2 pot onthe r850r is under the seat (left leg side) just above the airbox overflow oil collector box yoke.

 

[motobiker]

Now you have reminded me where it was... .

The picture wasn't for your benefit chap. But.. I'm glad it helped your memory problems.