I recently changed my sprockets and chain on my R1, I connected the chain with the master link and used the chain tool to secure (LOL) the link. I test rode it near my garage and the chain flew off! I have since been sent a new master link by EK and need to try again. I obviously didnt do it right the first time SO if any friendly LBers are close to Bermondsey OR Borough Market (5 mins from me) I would really apretiate some one doing it for me who has replaced a chain before. 
When joining the chain, you should have joined the ends using the master link, fitted the side plate/washers, pressed the side plate into place then then burred the end of the rivets on the master link.
Did you do all of these steps ?
Thanks for the reply, I didnt bur the ends, what is bur and how do u do it? 
Hit them with a punch and hammer to roll the pin onto the plate
Ok, I’m going to go do it now. Barry you said wack it with a sledge hammer, right?
It’s always best to use the correct tools, you wouldn’t want your chain coming off and locking the back wheel, be worth purchasing one for now and the future
I have one of these.
http://cgi.ebay.co.uk/Motorcycle-Chain-Riveter-Splitter-and-Riveting-Tool-/330448881247?cmd=ViewItem&pt=UK_Motorcycle_Parts&hash=item4cf049c65f