No jetting specs where listed by poster. With that said no one has said why a 16:1 ratio is bad in any set up. The other things I listed are jus for info. With all the pros posting in this post I don't need to say more
All these posts and no one has said why 16:1 would be bad. Diff mtrs are diff and can have more wear in areas than others. Add alky into the equation of oil ratio. Take it another step and diff oils lubricate and burn diff etc also
Box gap is wat I use to. Unless u have new plugs and make a full pass and then shut off...that's when a plug reading is done to tune. Pics don't show electrode ur prob not even close to lean