Sticky chain?

[EdStay]

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

 

[thomasinvancouver]

Chain gauge and pitch. Make sure it all matches. Rim/spur sprocket, bar, nose, chain. Nose sprockets are typically slightly wider gauge.

 

[scottr]

It sounds like the drive sprocket is worn and too much chain tension .
With the bar and chain on the saw can you pull the chain around the bar easily ?

 

[HarleyT]

Put up some pics!!!

 

[EdStay]

 

[EdStay]

 

[EdStay]

It sounds like the drive sprocket is worn and too much chain tension .
With the bar and chain on the saw can you pull the chain around the bar easily ?

No, it’s rather stiff

 

[HarleyT]

Take off the chain/bar and cover and snap a pic of the sprocket.

 

[EdStay]

 

[HarleyT]

Yeah, get a new sprocket before you damage/stretch out that chain.

 

[HarleyT]

I just meant the sprocket cover, btw.

 

[EdStay]

Yeah, get a new sprocket before you damage/stretch out that chain.

Will do. Would that explain the stickiness though?

 

[Mad Professor]

I see a narrow kerf 0.050 0.325 bar, and a 3 on the drive link 3/8 chain, those are a mismatch. Probably 3/8 0.050 chain on a 0.325 NK setup

whoops my bad the driver 3 is for gauge........0.050

 

[HarleyT]

Yes, put the chain on the sprocket and look at how the chain meshes with it, and you will see why.

 

[HarleyT]

I see a narrow kerf 0.050 0.325 bar, and a 3 on the drive link 3/8 chain, those are a mismatch

The three on the drive link means 1.3 mm, or .050 gauge.

 

[EdStay]

I see a narrow kerf 0.050 0.325 bar, and a 3 on the drive link 3/8 chain, those are a mismatch

 

[EdStay]

I just meant the sprocket cover, btw.

Wanted to be thorough

 

[EdStay]

View attachment 912590

That’d be a easy fix, the guy at the stihl place said they’d work though so I could likely take it back and swap’m. All the identifiers match on the packaging though...

 

[Mad Professor]

The three on the drive link means 1.3 mm, or .050 gauge.

I caught that after I already posted it.......

 

[EdStay]

Yes, put the chain on the sprocket and look at how the chain meshes with it, and you will see why.

It definitely sits in those grooves, I just can’t wrap my head around why that would add friction. I’m not experienced with this though so I’ll take you’re word. I’ll get a new sprocket but I likely won’t get the part delivered and swapped for at least a week. I got a big weekend of light clearing coming up. Would it be unsafe to keep this kit running as is to get me through the weekend?