In polishing a Stens replacement valve using the technique as demonstrated in Don's video, a line showed up on the stem. My guess is it's where the head is attached to the stem. I had to use the Stens for monetary reasons, but even in my practicing on the old stock Kohler valve, there is a faint line there as well.
I only polished it to the stock diameter, just taking the roughness off.
My question is, has the strength of the valve stem been undermined? Are these valves different than the Briggs valves shown in Don's video?
I'd sure hate to put this together only to have the head break off and do some serious damage to what will essentially be a brand new engine when I'm done.
Dale, wondering in Michigan