OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters Two Stroke Trimmers & Brushcutters makita line trimmer shagged flywheel key

I agree that if it is on a very small diameter shaft, that makes it less likely it is the key. Why not file up an aluminium key to fit the new dimensions, and see if that makes a difference? No cost, and you probably need the filing practice. Besides that, it had an aluminium key for a reason - the fact that it was sheared proves it needed to be aluminium.