One trick I've learned is to clearance the cover that holds the clutch lever. Every build I've done, the chain rubbed on the cover, making all sorts of weird noises. Easy to fix, simply remove the 3 screws that hold it on, no need to remove the clutch cable, rotate the clutch lever till it slides out, then take take your dremel (you do have one, right?) and grind or sand the place where it's rubbing. You don't have to remove much material, just enough to clearance the spot. You will see where it's rubbing, and it makes a HUGE difference in ridding your engine of all sorts of snaps, crackles, and pops.