Fueling problems. Cutting out

[legoman]

Got a bmw f650gs twin. Problem is it's just started to cut out. 4times on way home. Think I've got a clue. The petrol tank won't regulate it's self through the breather pipe. When I open the filler cap it gives a whoosh to say there's something a foot. Had the pipe off. Clear. All connections are clear. Had the thingy majig that controls the pressure release and all is clear..?? So why the whoosh on opening the petrol cap n is that making it cut out as it can't draw juice because of the pressure difference... Need help cos my pride n joy off the road now I can't play out. Need help before I call an independent bmw man

[sprintster]

If it is anything like Triumphs it will be blocked between the fuel cap breather hole and the pipe connector.Run a piece of garden strimmer wire down the breather hole.

[legoman]

Took all the pipes off and conecty bit plastic and metal and all clear n moving as they should as far as I can see. Don't under stand the pressure thing. Will give it a whirl tomorrow again. Just so I can scratch me head n wag my finger an me bike

[greenmachine]

Yes sounds like a blocked fuel tank breather. It will have a vent hole incorporated into the fuel cap and possibly a pipe somewhere tucked away under the seat typically. Easy check is to loosen the cap and go for a ride.... If it runs OK then that is the problem.

[frenchy3]

In hot weather there have been instances where the fuel pumps have caused problems and cut out. If you look on the BMW GS forum there is more information on this. Can,t remember if the fuel pump or fuel pump controller was the main culprit.

[Tonibe63]

On the 800/650 twins the common problem was the fuel pump overheating, it was the 1200 that had the fuel pump controller problem.
On your 650 when it cuts out open the filler cap straight away and see if it will start and run ok, if it does then it could well be the breather hole blocked causing a vacuum within the tank which leads to fuel starvation. If it doesn't restart then leave it for 10 minutes for the fuel pump to cool down and then try again.

[micksea]

spray some wd40 into the key hole of the filler cap,this should clear any dirt through there.probably the fuel pump as people with more experience of this particular bike have said.does it have a fuel filter in the tank next to the pump? might be worth checking that if it does.

[legoman]

Thanks for the advice I will look at the BMW forum

[legoman]

It's starts straight away after 1 or 2 jabs of the start button even if I'm moving still

[johnnyboy]

while travelling in spain last year on my gs800 it cut out several times in a 1 km stretch of road,it was very hot and i was low on petrol (no low fuel light)managed to get into a fuel station filled the bike up had a brew and on we went,from then on i filled up at regular intervals to keep the tank as full as possible, no more problems,looking on the internet later,many reports of the same,thermistor on fuel pump could be a reason.but the noise when opening the cap does make me think blocked breather,only my thoughts,am sure smarter people on this forum will sort you out.