Well MST you were right, there should be a synchro balance system there and it has been removed at some time in the past. It took me a while to find this out as the manual for my model of engine states it shouldn't be there at all!!! Possibly the crankshaft ( or the engine ) has been changed at one time and the only one available required the balance assy. Anyway I have one on order and will post when I complete the job. Thanks to you all.
