Yeah I am aware of the power rating differences between the kawis and kohlers. To be honest I really do not know which engine to get between the 850, 921, or efi 29.. I dont think id be able to demo all three of them either haha
I know it is nice to have more power but from what I read there is also a significant difference in fuel consumption between the three engines. I do mow some hilly terrain but nothing crazy. I also bag quite often.
Sorry to hijack the thread
I have the FX850 on my JF Z950 with 60" MOD and it is plenty of engine. I am getting around 1.5 gph in medium heavy grass. I know the drive systems are totally different from the Gravely's, but I thought I'd throw that out there for you to know anyway.