Wavey Davey

Now I know it is not everyones cup of tea, but I have been riding a BT1100 bulldog (02 Plate) for 4 years now, it is great fun and I have become emotionally attached to it - it has caused much marital discord at home!! Sadly it became rather unwell recently when the starter clutch seized, this was repeaired in time for the IOM TT but sadly whilst over the pond she failed again. and the AA had to get me back home. When it was taken apart I was informed that the cam shaft had snapped. Has anyone else had this heppen to them and could this be linked to the worked done on the starter clutch (completed by a Yamaha dealer using genuine parts)? As it occured 3 days after the yamaha dealer completed the starter clutchI cannot but feel a little suspicious.