Rough running 1100GS

[Rockeye]

Good evening all.I wondered if I could pick on your experience?

I have not used my Gs for several months apart from starting the old girl occasionally,she`s been on a trickle charger all winter however.I went for a ride today and the bike is running like a pig to be honest,at low rpm`s it will cough and splutter not pulling cleanly and making it very difficult to ride smoothly,if however you open her up above 3000rpm she pulls like a train and runs almost normally but does seem to have increased vibration.

On the overrun the bike will also pop and fart after being opened up as tho unburt fuel is being ignited on the overrun or the timing is slightly out? I`m gutted as was really looking forward to riding her now the weathers improving and seems she doesn`t want to play ball! The bike rode and ran perfectly when I garaged her at the back end of last year and has done nothing apart from being started occasionally and run only for a few minutes so as not to get too hot standing.

Any advice would be very much appreciated,I`m new to boxers and fairly inexperienced with there ways.The bike is a 96` 1100 GS with 71K under her belt.

Thanks in advance, Paul

 

[Ant1967]

If your leaving your bike for any length of time it's best just to leave it on a trickle charge and not start it at all unless you are going on a decent ride. The amount of condensation that builds up in your engine if you only run it for 5-10 minutes is unbelievable.

Tony

 

[Rockeye]

Thanks for the reply Tony,do you think this could have some bearing on the rough running at low rpm`s? and if so what do you think could be done to rectify this?

Paul.

 

[beermonster]

Try new fuel, a decent run, preferably involving a bit of dual carriage way blasting and see if that clears her throat.

known as an italian tune in some parts

 

[Rockeye]

I`ve tried that already,put expensive shell fuel in her and had a blast down the motorway to try clear the problem but sadly didn`t do the trick,really annoying as runs well above 3000 rpm albeit with the hgher vibration,having read another thread on here I`m wondering if it`s coil related especially with the back fire on the overrun?

 

[GS TRV]

Check my thread on low rpm hesitation.

I bet it is the coils

 

[Ian J Hartley]

Given that your bike starts and runs means you can rule out a lot of things.

I suspect what you describe is the bike runs OK when you open the throttle, but is a pig when you hold the throttle in a fixed position or closing. I'm wandering if you might have a knackered lambda probe. Running your bike for short burst over the winter,might well have killed it, maybe through corrosion.

The lambda probe plays an important part in cutting back excess fuel. At fixed throttle position and throttle closing.

 

[Rockeye]

Thanks for the repls guys,I have looked at the low rpm hesitation thread and thought mine may be the coils as a result.The Lamda probe is another thing I will look at also,I`ve just spoken to Motorworks whove advised me they have some second hand coils and leads in stock.

Do you know how to test the Lamda probe or is it simply a case of replacing it and hoping it cures the problem? The bike only sat in a dry garage from August until now with possibly a run a month to keep things moving.I did notice that the first 3 or 4 runs were fine,then the bike would miss and fart at tickover and when revved to 1500-2000 rpm,I`m hoping its moisture in an HT lead or the coil as we had a fairly damp and cold winter.

I`m going to pull the plugs this evening and see what they look like if I have time,my little lads birthday today so got to party first!!

Thanks again for your replys and suggestions,I`ll keep all posted with the result if and when I find it,any further ideas keep them coming!

 

[gerarddwatts]

Have you moved the tank?

Check that the outers on the throttle cables are properly seated in the throttle bodies.

 

[monkeyboy]

Thanks for the repls guys,I have looked at the low rpm hesitation thread and thought mine may be the coils as a result.The Lamda probe is another thing I will look at also,I`ve just spoken to Motorworks whove advised me they have some second hand coils and leads in stock.

Do you know how to test the Lamda probe or is it simply a case of replacing it and hoping it cures the problem? The bike only sat in a dry garage from August until now with possibly a run a month to keep things moving.I did notice that the first 3 or 4 runs were fine,then the bike would miss and fart at tickover and when revved to 1500-2000 rpm,I`m hoping its moisture in an HT lead or the coil as we had a fairly damp and cold winter.

I`m going to pull the plugs this evening and see what they look like if I have time,my little lads birthday today so got to party first!!

Thanks again for your replys and suggestions,I`ll keep all posted with the result if and when I find it,any further ideas keep them coming!

Didn't you say this was an 1100? The 'coils' thing is only for twin spark 1150s. You only have a single coil under the headstock.

Duff Lambdas (im my experience at least) seem to have more subtle effects than you're seeing. Definately on constant and light throttle openings but usually exhibiting a slight surge or pause rather than straight out rough running as you describe. You can just disconnect it and see what effect there is as a first test. It wont harm anything.

Popping on overrun can have lots of causes, like air leaks for example, but it could be the plugs not sparking and the unburnt fuel igniting in the heat of the exhaust. Again, spark plugs are a cheap and easy thing to replace first to rule them out.

Fuel can be a problem if left for a long time as it can jellify and cause problems in filters etc, despite putting new fuel in now. A fuel filter is only £10 even if its a bugger to change.

Did you say it used to run perfectly well on tickover? Now it is rough, but doesn't stall?

 

[Aidan1150]

Have you moved the tank?

Check that the outers on the throttle cables are properly seated in the throttle bodies.

 

[monkeyboy]

It would run rough throughout the rev range if that had happened but it's fine over 3k

 

[GS TRV]

It would run rough throughout the rev range if that had happened but it's fine over 3k

Exactly - mine was shocking when the throttle cable wasnt seated and much worse than the low rpm prob the coils gives.The coil issue im currently getting fixed is only noticeable at low revs. The bike picks up well with only a slight power loss at higher rpm.

Id check the coil first

 

[Rockeye]

Once again thanks for all your interest,replys and suggestions guys,I`ve checked the throttle cable seating and all seems to be fine,just taken the spark plugs out and look a lovely biscuit colour so seem to be ok,one plug does look to have a slight burr on one side of the electrodes though.

I think I will replace the plugs as suggested to rule them out as an easy and cheap fix,I have also looked for the lamda probe but can`t seem to locate one anywhere on the exhaust-is it possible this has been removed as a modification sometime,the bike has the standard exhaust can on it.

I`ve not removed the fuel tank at any point during the time I`ve had it so can`t have disturbed anything during my tenure.I have found a single spark coil and leads set on flea bay for around £54 which is a lot cheaper than motorworks as the coil and lead set was looking like closer to £100 second hand.

I`m off to get some plugs now and will pop them in and take for a spin and let you know how I get on.

 

[monkeyboy]

Once again thanks for all your interest,replys and suggestions guys,I`ve checked the throttle cable seating and all seems to be fine,just taken the spark plugs out and look a lovely biscuit colour so seem to be ok,one plug does look to have a slight burr on one side of the electrodes though.

I think I will replace the plugs as suggested to rule them out as an easy and cheap fix,I have also looked for the lamda probe but can`t seem to locate one anywhere on the exhaust-is it possible this has been removed as a modification sometime,the bike has the standard exhaust can on it.

I`ve not removed the fuel tank at any point during the time I`ve had it so can`t have disturbed anything during my tenure.I have found a single spark coil and leads set on flea bay for around £54 which is a lot cheaper than motorworks as the coil and lead set was looking like closer to £100 second hand.

I`m off to get some plugs now and will pop them in and take for a spin and let you know how I get on.

On an 1150 the Lamda screws into the collector box right behind the stand, cable runs up on the RHS to connect under the tank. Don't know if that helps on an 1100 though

 

[Rockeye]

Gentleman the swiss watch returns!

I popped down to the local motor factors as local bike shop was out of stock of plugs thankfully-managed to get the correct grade plugs for £4.20 each as opposed to £10 plus!

Just taken the bike out for a test ride and could have gone for miles as back to her old self,the old Bosch plugs I took out looked fine and were burning correctly,but one of the plugs must have been breaking down,leaving unburnt fuel hence the popping on the overrun as that has now stopped also.

I have learnt a lot and will certainly leave the bike on a trickle charger all winter this year as wont risk a knackered Lamda(sounds painful!!! ) and also learnt several other things to look for in the future should any similar faults arise.

Thanks again to all on this great site for your help and advice,hopefully I may meet some of you out and about during the summer.

Ride safe,Paul.

 

[Packer]

Unless your bike is fitted with an alarm or immobiliser I wouldn't even put it on a trickle charger.

Disconnect the earth terminal and just leave it, maybe give it a couple of hours of charging every three months. If it's a good battery it will be fine .

 

[GS TRV]

Result!!!