Hi there

Am looking for some advice on what on earth is wrong with my bike? He has just been serviced, MOt'd etc and the front brake assembly replaced as the master cylinder was broken. Now when rev'ing engine to change up a gear he is very jerky, for a moment won't pull forward causing a kind of kangaroo hopping type motion.

Also noticed when riding with my partner on another bike that my speedo is reading worng, says I'm going faster than I really am about 50% of the time anf the rest of the time seems to read ok..

Went back to guy who serviced it yesterday and he adjusted carburetor but this hasn't helped.

Any further advise as to what could cause this?