F650GS twin stammering and stuttering

[Tim Cullis]

Did a longish piste today in Morocco with three fairly deep river crossings, one of which was long. Some time afterwards I stopped to put on more layers (I was at 7800 ft) and when I went to restart, the engine cut out when I put it into gear. I tried again, same thing. Tried with more throttle, cut out again. When I gave it a real handful it hickupped, then continued.

Some miles later it cut out completely. I managed to get it started but then limped 70 miles at 45mph to Bikershome at Ouarzazate. Every time I gave it more throttle it stammered and stuttered. On hills I was down to 30mph.

In the morning I'm planning to take out the air filter to see if that makes any difference. I've already opened the tank to ensure there wasn't an air lock. I'm a bit concerned it might be to do with the side stand switch. Or maybe damp somewhere in the electrics.

Any suggestions gratefully received.
Tim

 

[Greg Masters]

Tim

I must start by saying that I don't know anything specific about these 800 twins - but my first thought is that you were at nearly 8000 feet. I'd be surprised if the injection system didn't have an air pressure sensor somewhere. Perhaps it has failed?

Do you know how to reset the ECU? I'd give that a try first.

Failing that, have you got watery petrol? (I assume that it's rained a bit down there recently). Try draining out a glassful and see what it looks like when settled.

Good luck!

Greg

 

[easyman05]

Tim

I must start by saying that I don't know anything specific about these 800 twins - but my first thought is that you were at nearly 8000 feet. I'd be surprised if the injection system didn't have an air pressure sensor somewhere. Perhaps it has failed?

or fuel sencor http://www.vosa.gov.uk/vosa/apps/re...BBDD4E60FDC9568025740B00300396&freeText=Blank

 

[Tim Cullis]

I started the day at 2000 ft at Ouled Berhil, climbed to 7800 near Lak d'Ifni, and am now down at 3800 ft near Ouarzazate.

I don't know how to reset to ECU.

I'm assuming the petrol is OK, I filled this morning and had done 100+ carefree miles before the problem.

Tim

 

[easyman05]

I started the day at 2000 ft at Ouled Berhil, climbed to 7800 near Lak d'Ifni, and am now down at 3800 ft near Ouarzazate.

I don't know how to reset to ECU.

Tim

take away the battery terminal cables and connect them/ not on the battery, of course/ for a minute - then you will not have to wait. Or just disconnect them and wait for half an hour. To be sure.

 

[Tim Cullis]

I had the battery terminals disconnected for 30 minutes this morning. No difference.

Initially every time I put the bike into gear it stalled. It eventually went into first without stalling, but then still stuttering badly on a test run. I stopped the engine at the top of a hill and it wouldn't go into gear again without stalling. Neither would it start in first with the clutch in. Nor would it roll start down the hill.

Then after a few minutes it started OK, but still with stammering.

Does anyone know how to disconnect the side start wiring?

Tim

 

[Frankk]

Tim,

As you engine only started cutting out after the river crossings I would guess that you have got some water in somewhere.....most likely the sidstand switch.

If you look at http://www.maxbmwmotorcycles.com/fiche/MainDiagrams.asp?mospid=50779 and go to diagram #61_1882(Vehicle Electrical System - switch/senors) you will see a drawing of the sidestand switch (3). It looks like it can easily be disconnected.....but depending on how it works you may need to "hotwire" the two wires after disconnecting. Good luck!

Frank

 

[Tim Cullis]

OK, problems sorted. They were both to do with a faulty side stand switch. We took it off, worked out by trial and error which was the 'on' position and gaffer taped it into that position, then cable tied it to the frame for sorting properly later. I've since done several hundred miles and it's fine.

Thanks for the help and advice.

Peter from http://www.bikershome.net had some Norwegian biker visitors and one of their bikes, a KTM 990 Adventure, also had problems. We were talking about how unreliable modern bikes are.

Tim

 

[Tim Cullis]

Hi Tim
Could you elaborate a bit more about which is the on and off position for the switch? thanks!

You disconnect the switch by using an 8mm socket on the nut at the bottom, then it comes loose. It's a bit like a coiled watch spring. There's a stud that rotates--presumably with the stand. All you do is to experiment to find out what positions it runs in, then gaffer tape the stud in the middle of the settings.

Tim

 

[Tim Cullis]

After riding home with the side stand switch disconnected, I eventually put the bike into the dealer to fix the top hose (again) and had the side stand sorted at the same time.

Well, sort of. It now happening again on an intermittant basis. After wacking the side stand up and down a few times the engine eventually continues when I snick it into gear.

Must find out from the dealer what they did to "fix" the problem. Although I really enjoy the F650GS, I'm getting to see the dealer on far too regular a basis.

Tim

 

[Klanky]

Cut out niggle

I've a habit of leaving the bike on the sidestand in the shed as opposed to the centrestand.

I wheeled the bike out of the shed yesterday and fired it up.

Engaged 1st gear and it cut out. Repeat - same again. Tried again...same result.

I already had an idea of the cause, so I flipped the sidestand up and down a few times and tried again. Result 1st time.

So it would appear that if you park up with salt and crud on the lower parts of the bike, there's a good chance the sidestand cut-out switch may stick if left for a couple of days.

Jus' thought I'd make Tossers aware.

 

[Tim Cullis]

I've been getting the same problem and also found that flipping the side stand up and down helped. Then it stopped helping.

However what seems to work is if--once the engine is warmed up, I wouldn't advise this on a cold engine--hold the revs at 4000 rpm, then blip the throttle up to 6000 rpm as you stick it into first. The downside is that it makes you look a real n00b to other bikers.

The dealer reckons it's the clutch. Certainly the bike has always had a huge amount of clutch drag; I always leave my bike in gear when I stop and it's very hard to move it around with the clutch in and I often have to click it into neutral.

The other problem I have (that I feel is associated given my previous experience in Morocco) is that the engine stutters under high load. Whenever I accelerate with a handful of throttle in 3rd or 4th gear it stammers and stutters at 6000rpm. Every time.

Tim

 

[birdseye]

there is no way that that level of clutch drag is correct. ideally you should notice no difference between rolling the bike around in neutral and doing so in gear with the clutch pulled in.

but I cant see a clutch problem causing the stuttering you talk of. stalling when going into gear makes sense, but once the clutch is home, its irrelevant to how the engine runs. What you have sounds like a fuel problem

 

[Tim Cullis]

I just assumed the clutch drag was a characteristic of the bike--it's been like that since day one and it's been in and out of the dealers enough times for them to pick up on it.

I agree there shouldn't be any correlation between the clutch and the stuttering, but check back on the symptoms on post #1 on this thread. When I taped the side stand switch the stuttering also stopped.

Tim

 

[Ed@Ford]

You disconnect the switch by using an 8mm socket on the nut at the bottom, then it comes loose. It's a bit like a coiled watch spring. There's a stud that rotates--presumably with the stand. All you do is to experiment to find out what positions it runs in, then gaffer tape the stud in the middle of the settings.

Tim

Although it is of no use to you at this moment, somewhere on ADVrider or some of the other F800 specificsites I have seen where a jumper was created which eliminated your problem, and kept the computer from sending fault codes. Maybe it related to the sidestand jiggling over rough ground causing engine shutdowns.

I will also suggest checking the fuel filter....but having reviewed the parts fiche....there is no fuel filter called out....just the "strainer". Most fuel systems (like the old F650 Dakar) had a strainer AND a fuel filter...which included the fuel pressure regulator and cost $50!!!

 

[chrisjk]

Tim,

When my 800 was new it stopped without warning and the dealer said the ECU log showed some sort of incorrect "sidestand event" IIRC, a month or two later, and one of the several software updates the bike has had specifically addressed some sort of sidestand issue.

Makes me wonder if your problems could be partly software related as opposed to hardware.

 

[Ed@Ford]

TIM:
An interesting experiment is possible. I'm assuming if you've disconnected the battery AFTER the sidestand problem, the keep alive memory was cleared...which probably deleted the sidestand event fault code. If you've ridden it since the stuttering, who knows what fault code might have been generated. So if time permitting & the dealer is amenable, check for faults now. There is a chance of a different fault code specific to the stuttering. THEN, undo the tape and see if the sidestand will piss off the computer and not allow you to engage the transmission. I would assume then you'd get a NEW sidestand fault.

FINALLY: Is the sidestand sensor connector 3 pin or 2 pin? If it's a 3 pin that means the sidestand could have a position SENSOR rather than 2 pins which would mean it's a SWITCH. A switch input to a computer is easier to deal with than a sensor input, as asensor input is either a varying voltage or resistance...where is switch is on or off. (open or closed).

I've been down this road with my friends '08 KLR650....it has a sidestand switch...nirmally we just jumper them out. Before he did this he did a pretty hard jump...the sidestand switch turned on diring the landing (the sidestand just jumped enough....and killed the engine....the runoff from the landing was a bit scary with a dead engine. If the sidestand spring was a little weak on the BMW, something similar could happen.

The sidestand sensor on the old F650 Dakar (single) could not be jumpered. I had one...I tried...no luck.

 

[Tim Cullis]

I've been getting the same problem and also found that flipping the side stand up and down helped. Then it stopped helping.

However what seems to work is if--once the engine is warmed up, I wouldn't advise this on a cold engine--hold the revs at 4000 rpm, then blip the throttle up to 6000 rpm as you stick it into first. The downside is that it makes you look a real n00b to other bikers.

The dealer reckons it's the clutch. Certainly the bike has always had a huge amount of clutch drag; I always leave my bike in gear when I stop and it's very hard to move it around with the clutch in and I often have to click it into neutral.

The other problem I have (that I feel is associated given my previous experience in Morocco) is that the engine stutters under high load. Whenever I accelerate with a handful of throttle in 3rd or 4th gear it stammers and stutters at 6000rpm. Every time.

Tim

I was away for a couple of weeks and when I returned I couldn't get the bike to keep going under any circumstances. As soon as the side stand went up, the engine cut out. I was about to have the bike recovered with BMW Assist (for the third time!) to the dealer and the recovery truck was on its way, but I decided to have a play and disconnected the side stand switch. Lo and behold, everything is fine.

I've just been for a test ride and the stammering at 6000 rpm has disappeared, so that was obviously connected. The side stand switch was replaced when it was in the dealer for the same problem last time, maybe only 1000 miles ago, so I have no idea what's wrong--software, hardware, whatever.

There's still the dragging clutch issue, so I will put the bike in this week.

Tim

 

[Koopz]

Tim,

I have the 800 and have noticed the clutch drag and assumed that this was standard for this bike as I have never had a problem engaging gear or noted anyone else posting about it, should I worry as the bike is going RTW later this year and I don't want to walk much!

Also, going back a bit on this post (and a bit off topic) how deep was the crossing on the bike (so I don't drown it).

S

 

[Howard Millichap]

I was away for a couple of weeks and when I returned I couldn't get the bike to keep going under any circumstances. As soon as the side stand went up, the engine cut out. I was about to have the bike recovered with BMW Assist (for the third time!) to the dealer and the recovery truck was on its way, but I decided to have a play and disconnected the side stand switch. Lo and behold, everything is fine.

I've just been for a test ride and the stammering at 6000 rpm has disappeared, so that was obviously connected. The side stand switch was replaced when it was in the dealer for the same problem last time, maybe only 1000 miles ago, so I have no idea what's wrong--software, hardware, whatever.

There's still the dragging clutch issue, so I will put the bike in this week.

Tim

Now you know why they're so cheap.