I am working on a Briggs 16 HP single cylinder engine which is model 326437 type 0 758 - 01 code 87041614. It is on a Lincoln weldanpower unit which has not run for some years. I have installed a new magnetron coil but only get a very weak spark. So weak that the spark is barely visible. I'm questioning whether the magnets in the flywheel have lost some of the magnetism from sitting for years. There is some residual magnetism left and it seems as if the South Pole of the magnet is on the outside of the flywheel which I think is correct. Is there any way of testing the magnet strength other than by changing the flywheel?