I had the old Victa out today, using it to mow both front and back lawns, the first time I've cut grass with it in 15-years!
My grandfather used to mow his lawns ultra short, like on the lowest or second lowest setting. And because he didn't let it grow tall, he always ran the engine just above idle. I never did find out why he did that, maybe he didn't like the noise, was afraid of it or was trying to be mechanically sympathetic. I guess that's why it runs so well despite being 50-years old and was used weekly for the first 30.