I do it to our Tecumsehs all the time. Good Luck wioth the stock diameter. didnt work for me. it moves once up to temp. I been putting mine at .020 over the stock diameter. The last one was .030. I get it cherry red (ring gear) the set flywheel down in it. Then cool not completely though so the heat doesnt effect magnet. Works just fine, no screws no locktight nothing.