thanks for all your comments guys, appreciated. I have taken it for a bit of a run now and the pinging noise seems to have become more regulat. Given I put new plugs in it the other day perhaps this now indicates the sourse of the noise to be a pre-ignition type problem and not so much a drive shaft issue (unfortunately). It's going in for a "head Job" later this week but given the low kms on the donk I am pretty peeved. I am now worried the oil rings may be seazed as the compression is down on 3 pots and the plugs were oiled from these two also.