Why would a 12GS run on one cylinder?

Gaz

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well, at least that's what it seems like it's doing.

I had a little off whilst pratting about in Wales off-road. I was rounding a left handed off-camber bend when it lowsided at about 15 mph, hit the deck and did a 180 whilst horizontal so that the front wheel ended up pointing back where I'd come from. It was probably on the floor for no more than 30-45 seconds but was sitting abut 20 degrees beyond horizontal (i.e. seat lower down the hill than the wheels)

It restarted fine but then
- was noisy
- vibrating much more than usual (a good sign that a cylinder is fecked)
- was intermittently very lumpy (occasionally smooth)
- prone to cut out at tickover
- had low power (max 60 mph possible on the struggle home)

the lads with me (Robbie C and Garry H) reckon the LHS cylinder is asleep.

An earlier incident that day had seen me chucked off the bike and small clouds of white acrid smelling fumes appeared when we picked it back up. This may have just been something from the battery spewing it's guts up over the exhaust. Or could it be connected to the lack of power incident that arose later on?

Anyway, there's nothing obviously out of place, or twisted, or bashed. Could the impact of the final fall have damaged something internally, or upset it's electrics or fuelling somehow?

If I start it from cold the the left hand header pipe does get hot, but might be just because the left pot is being pushed round by t'other one, rather than doing anything itself.

Help, I'm baffled (and am not the worlds best mechanic) :nenau
 
thanks very much, I'll fetch the plugs out and have a look for cracks etc
 
shake a stick

Gaz'.
My 1200 has been on the floor:blast , upside down:eek: .more times than you can shake a stick at:D . Hopefully it is nothing sinister and just a plug or something. Best start there...........................:beerjug:
 
Plug lead

Check the lead going to the plug - it is not a single line. There is a clip just near where it drops into the pot under the black plastic protective thingy. Your fall may of dislodged it. Takes 2 secs to check.
 
Check the lead going to the plug - it is not a single line. There is a clip just near where it drops into the pot under the black plastic protective thingy. Your fall may of dislodged it. Takes 2 secs to check.


I had a problem with the coils on my plugs (there attached to the leads) This made it feel like it was on one cilinder. Infact it was just one plug not functioning.
 
Update :- the bike spent 90 mins on Clark's diagnostic machine today and it flummoxed it and the mechanics.
They don't know what's up with it. They don't think it's mechanical, it's not the plugs or coils and yet and it is definitely running on one cylinder.
Back again tomorrow for another bash ...
 
Update :- the bike spent 90 mins on Clark's diagnostic machine today and it flummoxed it and the mechanics.
They don't know what's up with it. They don't think it's mechanical, it's not the plugs or coils and yet and it is definitely running on one cylinder.
Back again tomorrow for another bash ...
Did they change the plugs or just check them its so common that the valve cover shifts ever so slightly and puts a hair line crack in them which causes it to arc out
 
I had a problem with the fuel line going to one of my cylinders twisting, causing the engine to run on only one cylinder
good luck
 
Thanks for the ideas chaps, but the answer was that the low speed fall had bent (but otherwise not marked) an injector nozzle. So 2 weeks and £200 later I'm getting the bike back today.
Either I was very unlucky or they really are that fragile. Am now thinking long and hard about whether it'll go off-road again.:(
 


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