Sticky chain?

[EdStay]

When you took the sprocket cover off, there was a smaller cover over that spring and hardware, correct??

Correct

 

[EdStay]

See if there's an obstruction around the brake band or between the band and the clutch drum. Could be causing friction as it goes round.

 

[JayPopple]

Heya folks,
Got this used ms250 up and running, but still can’t get it in good working condition. Bought it a new bar and chain and using stihl oil to rule out those variables. I’m certain my chain isn’t too tight as I can pull it up enough to reveal the drive link. The chain, however, feels like it’s feeling resistance. When I release the throttle it doesn’t coast to a stop smoothly, rather it rapidly slows to a halt.
Could it be the chain sprocket? When the bars off, the chain sprocket spins free after the throttle is released , but maybe without the chain and bar on it can overcome whatever is gumming it up. I’m not sure that’s the problem but maybe it needs to be lubricated or something.
Any other ideas?
Appreciate the time folks

Does your bar have a roller tip. Try greasing it if you do. Make sure a drive link goes around the bar easily. Check the specks on the bar and make sure they match the chain.