New sprocket causing issues?

[Bag of Nails]

Got this new Gb titanium bar very heavy 44" for milling on my 395xp so I had to swap out my 3/8 sprocket for a 404 and now I can only pull the starter rope out when the chain break is off won't budge an inch with it on and even when it's off and I can get a good pull it's not really wanting to turn over wanted to get some thoughts from you guys on what I'm doing wrong before I start messing with it.

 

[Maintenance supervisor]

Take the bar and chaim off and see if you can rotate the clutch drum independently of the clutch or crank , if it doesn't or is very difficult something is wrong.
Either the bearing is froze or the alignment of the drum and oiler is off or the oiler gear is shot or something. Don't run it though.

 

[huskihl]

Guessing your clutch drum teeth aren’t engaging the oil worm, and the clutch is tightened up against the drum, not allowing the motor to spin independently from the drum

 

[HumBurner]

That was my thought too, as this just happened to me this year when swapping sprockets on a saw.

The worm had just enough wear that it wouldn't seat right. Chain would spin freely without clutch cover and tightened chain. New worm and all was right with the world again.

The wear was minor and not even on all of the slots.

The take away lesson was always double check the worm-clutch seating before retightening.