Chain won't move, sprocket looks ok.

[Yawiney]

Was cutting some brush and chain pulled in a small blackberry branch and chain came off. Turned off saw. Seemed like it kept spinning, (inside) longer than normal. Put chain back on. Wouldn't move. Got another chain, same thing. It doesn't move around the sprocket. Looked at the sprocket and it doesn't look or feel like there's grooves in it.
Could it still be the sprocket?
I've had the chain come off like that before and never had this problem.
Thanks for any wisdom here.

 

[cookies]

remove the bar, clean the groove and tip sprocket. remove the clutch drum and clean/inspect for vine wrapped in it and check/grease the bearing.

 

[Wood Doctor]

What saw are you using? Got a Pic? How old is it? Etc. Believe it or not, your chain's pitch may not match the drive sprocket pitch. That will throw a chain faster than just about anything,

 

[Yawiney]

remove the bar, clean the groove and tip sprocket. remove the clutch drum and clean/inspect for vine wrapped in it and check/grease the bearing.

I didn't remove the clutch drum. I could check that. There was no sign of anything getting in there. I would think i'd see something sticking out. But i'll check tomorrow.

 

[Yawiney]

What saw are you using? Got a Pic? How old is it? Etc. Believe it or not, your chain's pitch may not match the drive sprocket pitch. That will throw a chain faster than just about anything,

MS 250. Less than 3 years old. I cut my own firewood, but it's not my business. Both chains fit the saw and worked fine on it before. it's only happened twice before in 3 years, but both times i put it back on and the only issue was the chain had gotten dulled.

 

[cookies]

MS 250. Less than 3 years old. I cut my own firewood, but it's not my business. Both chains fit the saw and worked fine on it before. it's only happened twice before in 3 years, but both times i put it back on and the only issue was the chain had gotten dulled.

if possible post pictures of the clutch/ drum/ chain/bar. the sprocket on the drum might be worn out binding the chain in it. double check the chain brake is off...guilty of that one myself once or thrice.

 

[Yawiney]

if possible post pictures of the clutch/ drum/ chain/bar. the sprocket on the drum might be worn out binding the chain in it. double check the chain brake is off...guilty of that one myself once or thrice.

Oh shootz! it is possible the brake was on. ha. I'll check that before removing the drum. report back tomorrow.

 

[stihltech]

The drivers on the chain boogered up? Pretty common when a chain jumps.

 

[Okie]

Turn the chain brake OFF

 

[Bob Hedgecutter]

Derailed chain- damaged drive links be my first guess with no photographs to back up as evidence.

 

[Yawiney]

Alright, i'm an idiot. brake was on.
Thanks to all for the troubleshooting help.

 

[Wood Doctor]

Well at least now you know that the chain brake works. Okie is a mind reader.