Got the bike serviced last week £350 sterling. The valves were adjusted and now I can hear them rattling under the cover. Is this normal? Also I'm sure the bike has lost some power. I think i'll start to do my own servicing now, all they did was set the valves change the rear pads, change the oil, change the air filter and give all the moving parts a general lube. I could have done that in a day. I'm going to buy a workshop manual now.