1100GS Running Poorly/Backfiring/Cutting Out

[hovis]

OK. I finally found some time and tried to fix my GS. New hall sensor was fitted but this unfortunately did not fix the problem
Bike is still running poorly. It looks like either this hall sensor if damaged as well or it wasn't hall sensor in the first place.

I tried to record the noise the bike is making but it did not work very well on a phone recorder.

http://www.youtube.com/watch?v=tuwSV96um_k

 

[Uncle Crumpet]

OK, I've given my 1100GS to Cyprys on long term lone but it's turning into a white elephant.

Had to change the clutch and then front brake master cylinder. THought it was all good and also balanced the throttle bodies using a DIY manometer (which I've done several times before).

When Cyprys picked it up to ride back to Edinburgh it died slightly at higher speeds and now it's cutting out and backfiring.

He's got new plugs for it and I advised checking ignition wires, sidestand cutout and fuel tank breathers although diagnosing at a distance is hard. The throttle cables ARE properly seated.

The backfire would indicate too much fuel in the mix I suppose? Would the balancing have cocked things up because it ran passably before? Anyway, I can't really answer questions on how it's riding but I'm sure if anyone has any ideas Cyprys will be along to illuminate things.

Cheers

I think that may answer your question,"was all good" then you did something and it wasnt?? Not taking the piss, i just know how many times I have been the cause of a suddenly occuring problem when working on bikes.Get the balance done again.

 

[waterloo700]

Seems like the best help you can get is the name of a good independant specialist near you who can diagnose your problem first hand.

Or you could just carry on throwing money at it based on our collective wisdom.

 

[hovis]

Seems like the best help you can get is the name of a good independant specialist near you who can diagnose your problem first hand.

Or you could just carry on throwing money at it based on our collective wisdom.

so it seems. Might be my next move.

 

[dogzbody]

My 1100 started missing a week ago, started and ticked over and would run well then suddenly feel like it was running on one. Decided to give it a full filter replacement service before digging deeper, and replacing sensors etc as advised on the forum. on replacing the fuel filter i siphoned as much of the fuel out as i could, then in my ignorant non mechanic way turned the tank over and tried to get the remaining fuel out via the filler cap, i noticed some red lead coloured flakes of paint in the filter of the jerry can funnel. On removing the fuel sensor plate I found the bottom of the tank wing (where the fuel pump filter bag sits) full of sheets of paint from the inside of the tank. I have cleaned the tank out as best i can and have washed it through with fuel, and put it back together. The difference was noticeable straight away. i will have to take it on a good run to confirm my suspicions, but am convinced this is the problem. Unleaded fuel and whatever additives they put in it have caused similar problems with fibre glass tanks, and some fuel lines, blocking carbs with a sludge. It costs nothing to turn the tank upside down and see if you get any crap in a filter.

 

[warmshed]

It seems that BMW has not learnt from previous faults, My R100RS gave me problems when its red tank lining kept blocking the filters.

 

[dogzbody]

Been doing a bit of thinking and have come to the conclusion that the de-lamination of the tank lining is probably due to a previous owner dinging the tank,(the decals are from a later model) and not fuel additives. Also have cut the old fuel filter in half and it was clean, which is good news. the fuel pump filter bag has been doing its job.
I am still convinced that the sheets of paint have been masking the fuel pump filter bag, which would cause the intermittent running. So if you are aware of a tank repair, or buy a second hand fuel tank, i would suggest changing the fuel filter yearly.

 

[Fanum]

Anyway, when my fuel pump failed last year it did not sound noisy but it did give similar symptoms, and if the complainant did not notice it, whilst wearing a crash helmet at speed, then it wouldn't be mentioned or was forgotten during his explaination. Mine primed when power was applied but died within a minute or so and eventually failed completely.

Which part do you reckon they'll enjoy replacing the most?

Also, the OP should do a search here for the reference to the cheaper motorcar pump if he needs one.
I did it for him.

Can I just double check this please?

My fuel pump is on its way out.....are you saying that a £32 quid audi (or other) pump can be used instead of a £180 quid BMW part?

Any mods needed?

Very happy to have seen this if it's correct.........

 

[Deleted account 231002001]

I can't remember under what conditions my 1100 ran rough and cut out but I do remember what was causing it.
Blocked drain in the filler neck that caused a build up of water in the bottom of the tank.

 

[nick.ct]

Just a thought. Has a different exhaust been fitted, as in for example, an aftermarket one being replaced with an OE one and the codeplug not been changed? This could result in the symptoms described.

 

[davegs]

Been doing a bit of thinking and have come to the conclusion that the de-lamination of the tank lining is probably due to a previous owner dinging the tank,(the decals are from a later model) and not fuel additives. Also have cut the old fuel filter in half and it was clean, which is good news. the fuel pump filter bag has been doing its job.
I am still convinced that the sheets of paint have been masking the fuel pump filter bag, which would cause the intermittent running. So if you are aware of a tank repair, or buy a second hand fuel tank, i would suggest changing the fuel filter yearly.

We had an audi pump fitted to an 1150 in bulgaria worked fine.

 

[Pekkavee]

Can I just double check this please?

My fuel pump is on its way out.....are you saying that a £32 quid audi (or other) pump can be used instead of a £180 quid BMW part?

Any mods needed?

Very happy to have seen this if it's correct.........

This works fine.
Pump

Pekka

 

[hovis]

Right...We finally fixed the bike...It was Injectors...after fitting new ones (second hand that is) bike was like a newborn. Thanks for all the help....