Funny but I just closed up a T653R. I had a lot of problems with this magneto. Used a John Deere pony motor coil ($67). Brillman sells a Maytag coil for $175, Ebay sells them for $125-150. The Deere coil requires the laminates be 7/16″. It has a nice hot spark, but everything needs to be right. The points had a loose point on the movable arm. This is corrected by peening the point. Also, make sure one primary lead goes to a good clean ground. All the connectors must be in good condition too as I had problems with these. Brillman has a condenser that works well with these. Their part #B4012-005, for the IHC magneto H1.
Hope this helps.
