Originally Posted by dsond
When the rod snaps usually the snapped rod hurts the crank pin,as a result a new rod will have a bit play on the crank pin.The solution is to add a shim if this is what happened..
A snapped rod does give a lot of dirt inside. You have to take out the brarings and then clean them out as also the crankcase to be sure all dirt is out. If you have not done that the yes, some left over dirt will damage the plug.
And after changing the P/S/R set you always have to check the head clearance, maybe it is to low.