After alot of work taking it down and finding wrong parts etc fitted,ie.the engine is a 300cc yanmar L70 engine fitted by a UK firm called Barrus that part is original what isnt original is the inside drive/transmission cover which had been modified badly and was made to fit on a 400cc engine which I have found to be about 1.5" longer,although Barrus confirmed that the engine was original and chassis numbers were all ok they have not been very helpful.I am trying to find their workshop manual the quad is a 1993 D bat. If anyone could help with a workshop manual for the 300cc yanmar powered D bat it would be apreciated thanks if you have read this far Steve.