Hey guys, sorry for thr delay - been moving house so i've been a little distraced. Firstly 'd just like to thank you all for being patient with a newbie and taking the time to reply.

TuckerBag, thank you for the direction to the manual, i have had a look and its damn useful - keeping it open on my laptop while i work on the bike from now . i think the pistons are fine. i've got an inline fuel filter so i dont think its the rust - it could be the carbies - i disconnected the cables and oil pump line, then tried to take them off, and its impossible! one of the 4 bolts comes out, but the other three are stuck fast. i sprayed them down with lubricant and im going to give them a go tomorrow. Any ideas for getting them out if that doesnt work?

As for now, im going to head down and check the CDI's .

Thanks again guys.