You're right, I looked up my specs in my little notebook wrong. I'm new to gas engines so I bought 3 used engines to learn on. I have been trying props and trying to tune the engines and have been keeping notes. I accidentally gave the benchmark for the wrong engine. The corrected rpm for the 24EI is 7850 with the 18 x 6. Sorry if this caused you any confusion bobreib. Didn't mean to sound like a idiot