your gonna have to open the carb up and give us the jet sizes for the main and the idle, they usually come with the same thing but not always.
thats a pretty big carb for that setup ( im running one too so thats not a slam) Just be patient and expect to have some work ahead of you, you cant just hum a big phbh on a motor like that and have it run perfect.
Check for air leaks
see what you have for jets
search the wiki and follow the tuning guide for that carb.
in most cases the idle/pilot jet that comes with the carb are too big for a little metra 65 (this is my experience)
you need to work through and find out if you have a low end bog due to a lean condition, or a rich one....
Also, maybe it me but my metras always run shitty before they are broken in and have no low end till the clutch wears in and its got some milage on it. Did you try advancing the timing/ retarding the timing? Are you running all those base gaskets?
welcome to tuning. Its way more then humming the carb on the bike lol
In the end you will be satisfied with your setup, its a great one, but dont think you aint gonna get real good at taking that goddamn float bowl off and the raising and lowering needles