71362809 is a possibility. It has a piston inside a piston so to speak and is used on R50's and 87'F3s. It will 'throttle' the oil so as the tube approaches in the cradle it just eases in nice and soft. If a R40-50 or other late models don't do this there is an o ring blown in the piston bore. The Cyl does not have to be removed to repair this. Undo the chain, knock the plug back and remove the snap ring and pull the assy out from the bottom. look at a parts break down and see where the oring is missing and replace it for the feathering action. The orfice plug_plunger was also reduced in size many years ago as an field improvement via service bulletin.