dear ken: we have 2 1978 rd400,s , unfortunately we don´t have two seats but, we have alot of extra stuff... we need a crankshaft end , that operates the points (a cam style end that opens and closes the 2 sets of points , we think it bolts to the end of the crankshaft) , but don´t have a diagram in the factory shop manual purchased from YAMAHA (This book is not very good) Could you send us a blow up picture of that part of the engine . do you have a Haines or Clymer book ? we bought the bike apart so this stuff is a bit of a mystery . thanks darrell and ken ,calgary , alberta ,canada 403-371-7337 collect