FJ_Kevin, You mentioned somewhere, that you had been welding the clutch cover of some of your YZ-engines. We have a small crack in the clutch cover of -87 490. It will be fine for this season with a bit of epoxy, but I'm hoping to weld it during the winter. Do you know what sort of Magnesium mixture is used in the sidecover? What sort of filler did you use?
The crack is about 5cm below the starter shaft and I'm worried it might be getting larger.