I'm using a 10X5 prop and Brodak fuel 10-11-11 on a light Oriental, about 38 oz. It doesn't turn the RPMs that the Brodak engine does. I was hoping for a 424 run but I guess that's out. The LA also weighs quite a bit more than the Brodak. About 7 Oz. I think. The problem with the Brodak 40 is that they are hard to get. John gets a batch in and they are gone in 1-2 weeks. I recently bought a Saito 40. Anyone out there have any experience with a Saito on CL. It sure weighs a lot more than a Brodak 40.