First off, WELCOME to the POPS site!It's always good to see new people join!
I used gas and brake cleaner to cut the lube out of the clutch. Even with that it was near impossible to remove.
Oohhh.... Bad...
Gasoline's a bad cleaner - there are lots better things out there.
Next time, try, believe it or not, Simple Green. Acetone's also another good grease remover.
Simple green everything, then use hot (as you can stand), soapy water and a brush. Give it a couple baths and see how it works.
Acetone is great for final surface cleaning. Use it on the faces of the clutch.
Check your clutch and make sure that the marks line up for the balance. They will usually have some sort of marking - maybe ink, paint, a cast nub - something. There should be one on each clutch half. If you got it put back together w/o them being lined up, well, there could be the vibration issue.
Is your belt new? Old? Do the sides of it have a shine or are they dull?
How about the clutch faces? Shiny??? Take a scotchbrite pad to them and lightly rub any shine off the faces. - then acetone them.
With a new belt, you need to break it in. (Yes, I was surprised to hear this too).
Run it fairly hard for about 10 minutes and then let it sit for a while. The idea is to heat up the sides so that the rubber sort of seals itself and then it, for lack of a better word, tempers.
Do this on all new belts and they'll actually last a bit longer than normal. Weird, but it works.
It also seemed to be running a little rich at idle. The throttle seemed a little sluggish in the first 1/4. I want to make sure the clip on my needle didn't slip.
The clip can't slip - it's stuck in a groove... :?
Well, it's SUPPOSED to be stuck in a groove...
The needle doesn't really do much until you get closer to the 1/4 throttle setting anyhow, so it sounds like you're working with the air screw.
Here's a little info on jetting. <---- clicky on the linky!