That would be about 4 ounces (~1.2 dl) per full tank.
I do 6 ounces per tank, so indeed, 4 ounces is not too much.
I never understood this "every other tank" method that some people are following. Why run one tank without premix but the next one with premix? You only need the extra lubrication on every second tank?

 

I do 8oz per full tank so about a 1/2 oz a gallon. I carry the Rotary Bum 4 pack 8oz bottles kit and usually run the gas until the fuel light comes on. I am straight piped so I don't have the worry of possibly clogging the CAT with using that much premix. The brand I use is the Lucas 2 cycle oil which runs $9.99 at the local auto parts store.

 

i dump 8oz of idmitsu/tank. i just measure it off the bottle window

 

Thanks for that info. To clarify, you can consider this “not premixing”. So, if you want to try it, go to the amount some have posted. You may see a slower decrease in compression. In fact, I would say it’s very likely that you will derive benefit.