You should be able to cycle the chain (with a gloved hand) freely. A properly tensioned chain will have some drag but not be overly difficult to cycle.
Not trying to insult your intelligence but just trying to cover the bases, did you verify that the new bar and chain pitch match that of your rim or spur sprocket on the clutch? I'm not sure if the 435 uses a rim or spur, but if it uses a rim sprocket, make sure the chain is properly seated in the rim and not alongside it.
If that all checks out, I would remove the clutch cover, bar, and chain and sparkplug. Pull the engine over with the recoil starter and observe the clutch as it rotates, looking for wobble or anything out of the ordinary. Next, rotate the outer clutch drum by hand checking that it spins freely. If no issue is detected then your problem lies with the bar/chain combo or the clutch cover/chainbrake itself. Closely inspect the chainbrake area of the clutch cover checking for signs of any rubbing and make sure it is clean and functional.
If you mount the bar and chain, does the chain cycle freely before you install the clutch cover?? I know it's only loosely mounted, but this can help point you in the direction of the problem. If everything seems normal at that point, how about installing the clutch cover and only lightly seating the bar nuts leaving the chain loose? If still good, tighten the chain and try again? Something is amiss somewhere..
