Re: I need help with this one!
With the motor choked, does it die if you rev it up?
Define "hard to start." are you kick starting, or riding to start? Some motors are finicky with the choke in regards to starting. On my mb, I have to set full choke, and kick it over. It sounds like it's trying to start, but it won't fully come up. Then I set it to just under half choke and kick it again, and it starts. I leave it this way till it's warm.
If I don't do the full choke on the first kick, I have one heck of a hard time starting the bike.
If spraying carb cleaner doesn't change anything, I'd say you don't have a vapor leak.
Also, I'd stick with the 32:1 mix if you're using a good oil. You said the plug was oily and black, have you tried adjusting the E clip on the needle?