Help 950 has no power

[boboneleg]

The story so far, it turns out its not running weak as I first suspected, the reason the exhausts are so white is the at the rear spark plug is not firing which means the un-burnt fuel is going into the end cans then burning off which is the cause of the look of the exhausts, I changed the plug it run for a while then the plug was all fouled up, cleaned it and it did the same thing, long story into a short one, engine out rear cylinder off and found a small piece of metal in there but I can not find any damage to anything and nothing obvious as to were the metal has come from , apart from this the piston, barrel and head look in very good condition the bikes done 35,000 miles and has a full service history

Thanks for all the ideas I'll let you all know if i find the cause

It's not a piece that's dropped off the plug is it?

[Ashley M]

I don't think so the plug looks ok and it was still working before i took the engine out