We have been having trouble with our JD 520. It keeps taking points and once in a while condensers out. I rebuilt it last year and it ran fine until fall come, it started back firing, and points woulds only last a week. Now when we set the points the key is off and when we turn the engine over there is a small blue spark that occures. I thought there wasn't suppose to be power when key is off. Also it will run uneven with the generator hooked up to charge the battery. It is our everyday user and would be nice to have it working with out fighting it. Any ideas? Thanks