Not sure if anyone is interested but I thought I would update this thread... So I tore down the engine and found that someone had been in there and had fixed it before....not! They had forgotten to put the peg in the outer crank bearing behind the ignition. The bearing had rotated and blocked the oil way starving it of oil. It rolled like a spherical bearing lol there was so much play! I took the crank to Dave Branch who had a good secondhand bearing with a peg (Not available from Suzuki), replaced the odd 2 conrods (2 different types on one crank plus one was bent) replaced a main bearing and welded it up for me. Started her up at the weekend after putting it back together with a new to me set of cases, new wiseco rings and a hone, new camchain, camchain tensioner blade, manual tensioner and lapping in of all of the valves, Pleased to say she sounds a lot better now!