Factory shows 72 / 84 or 73 / 73 with 6.5 power valve for 750 cfm
Looks like they have been changed, most likely for similar issues. The factory setup is to get it within range. Changing jets by +/- 4 usually means there is something else going on.
Yours being black might be the power valve is damaged, incorrect float height and carb is flooding. Incorrect timing would lead to pour performance, but it should still start.
Not having a choke would be bad for cold starts but should be fine once warmed up