johanp
Race Dog
On our recent Namibia trip my buddy's wife's bike(2010 F650GS) suddenly lost power on the way back, before Aroab. We luckily had a backup vehicle so it was loaded and that was that, no time to waste.
The bike idled rough and sounded like it was running on one cylinder, you could also smell fuel vapor and hear it blowing from the tip - first assumption was that a spark plug had somehow popped out.
It was taken to Bavarian who confirmed our suspicions, a plug had come loose and wreaked havoc - the threads in the plug hole were damaged badly(at the bottom iirc) so the head had to come off to be sent to engineering which then of course meant new head gasket, head cover gasket, new plugs, new coil,etc. At least they could check the valve clearances while they were at it. R7500 odd later and she's running nicely again.
Just some background:
-Bike was bought at 37000km
-Owner self serviced(alarm bells?)
-Bike's been running nicely, other than a failed cam chain tensioner in the Eastern Cape. Fuel cons, power etc has always been the same as the other 2 F650GS twins in our group.
-This happened at around 58000km, it was almost due for a spark plug service
What could have caused this to happen and take THIS long? I guess we could assume the previous owner replaced plugs at 20k and either over, or under tightened. I'm not sure but I don't think plugs were replaced at 40k but even if it was, that's 18000km ago and it let go very suddenly.
It's a bit amazing that the bike ran so well with a plug that looked like that, I guess this means it could have been loose for a while?
Thoughts?
The bike idled rough and sounded like it was running on one cylinder, you could also smell fuel vapor and hear it blowing from the tip - first assumption was that a spark plug had somehow popped out.
It was taken to Bavarian who confirmed our suspicions, a plug had come loose and wreaked havoc - the threads in the plug hole were damaged badly(at the bottom iirc) so the head had to come off to be sent to engineering which then of course meant new head gasket, head cover gasket, new plugs, new coil,etc. At least they could check the valve clearances while they were at it. R7500 odd later and she's running nicely again.
Just some background:
-Bike was bought at 37000km
-Owner self serviced(alarm bells?)
-Bike's been running nicely, other than a failed cam chain tensioner in the Eastern Cape. Fuel cons, power etc has always been the same as the other 2 F650GS twins in our group.
-This happened at around 58000km, it was almost due for a spark plug service
What could have caused this to happen and take THIS long? I guess we could assume the previous owner replaced plugs at 20k and either over, or under tightened. I'm not sure but I don't think plugs were replaced at 40k but even if it was, that's 18000km ago and it let go very suddenly.
It's a bit amazing that the bike ran so well with a plug that looked like that, I guess this means it could have been loose for a while?
Thoughts?
