Yes, I'm talking about the (pre Surpass) OS FS-120 with 2 valve covers bought back in the early 80's. I flew a 1/4 Cub with this engine and it was perfect. I'm looking to fly this plane again and I'm wanting to go with a modern 4-stroke gas engine. I was looking at the FG21 specifically and was hoping it would at least have as much power as the older 120 on glow.