Should I be adding lead or other additive to the gasoline for my '64 D-17 Series IV? The manual mentions 91 research octane, or something similar.
I've run maybe a half-tank of premium unleaded thru (92 octane R+M). The tractor acts like it's running on the lean side (a little choke seems to smooth the engine sound a bit and improve power output). Before I go adjusting the carb main jet, just want to make sure I'm not goofing up with my choice of gas, in particular unleaded.
And how about gas with Ethanol? Here it's cheaper (and higher octane) than gas without.