Ive got a brand new set of cush rubbers fitted. Plus my chain has no tight or seized parts so im totally out of ideas. Defo not the cranshaft nut as there is no engine rattle and the engine runs sweet as a nut and the valves are all within spec. Im worried it might be the gearbox thats causing it but i have no idea. Hopefully they will find out and get it sorted on saturday. Need to use the bike 40 miles a day till then tho so im hoping its not going to get worse.
Hope its just the rubbers you need good luck.