Stihl 011 3/8 Picco 7 tooth sprocket NLA?

[dwaugh]

Not sure if I should start a new thread, but I had one on a piston stop for the 011 (consensus was the metal one I had was not good to use, so go for rope or impact), I got the clutch off to lubricate the bearing, but figured I might as well replace the bearing and the spur sprocket. The local dealer had to order the bearing, but the 7 tooth spur sprocket 1120 640 2005 seems to be no longer available (NLA). The dealer is going to explore that further. Not sure if the 6 tooth sprocket is NLA, but I have seen more of those online both Stihl or aftermarket. The wear on my current sprocket is not bad and the saw sees low use currently so this is hardly a priority. I guess I'm wondering if anyone familiar with these saws knows of a drop in replacement, or if I could run the 6 tooth sprocket without needing to shorten the chains I have. Thanks.

 

[Mad Professor]

Can't see the worn area on the spurs.

Ebay has aftermarket 7T rim style $26 shipped.

 

[dwaugh]

Can't see the worn area on the spurs.

Ebay has aftermarket 7T rim style $26 shipped.

Yeah, the wear is not to bad. (Photo below) I just figured if it was in stock/available at the dealer and I had the clutch off I would replace it and keep the old one in reserve. If the dealer doesn't find something I will go the eBay route like you suggest.

 

[Mad Professor]

Yeah, the wear is not to bad. (Photo below) I just figured if it was in stock/available at the dealer and I had the clutch off I would replace it and keep the old one in reserve. If the dealer doesn't find something I will go the eBay route like you suggest.



View attachment 1226788

It's getting there. Would be good to have a new sprocket next time you replace chain.

 

[Valpen]

The last one I got for my 011AV on eBay in 2022 was made in the USA by Oregon... It was exactly the same as my Stihl sprocket...
Note, I was running a 6T sprocket, not a 7T.

If you search on eBay for "NOS Oregon 28016 Spur Sprocket for Stihl 009, 010, 011, 020", you will get plenty of hits for 6T sprockets.
I don't know if Oregon made a 7T version. Someone else here probably does...
I have no experience with other aftermarket versions.

 

[dwaugh]

Can't see the worn area on the spurs.

Ebay has aftermarket 7T rim style $26 shipped.

Heard back from the Stihl dealer it is really NLA so I will go that (eBay) route you suggested.
I ordered this rim sprocket kit, hope it fits, not sure if this is the one you saw https://www.ebay.com/itm/3849839427...T8WeHWQ4SlYrV5RCRT4jrwIJE=|tkp:Bk9SR6y7--X8ZA

 

[Franny K]

I see the second picture in the rim drive kit shows 3/8lp but the first picture seems to just show a 3/8 sprocket. Kind of curious if it is a mini spline or generic small spline kit.

rsm 375 7 rim sprocket I searched this and it seems not technically for 3/8lp but will work ok in the saw size you have.

 

[dwaugh]

I see the second picture in the rim drive kit shows 3/8lp but the first picture seems to just show a 3/8 sprocket. Kind of curious if it is a mini spline or generic small spline kit.

rsm 375 7 rim sprocket I searched this and it seems not technically for 3/8lp but will work ok in the saw size you have.

I assume you are talking about the kit I linked to (that I just ordered)? Yeah, I'm not convinced it will work. I'm running 3/8lp now but I wonder if the sprocket is really 0.375... Guess I will find out

 

[Valpen]

I assume you are talking about the kit I linked to (that I just ordered)? Yeah, I'm not convinced it will work. I'm running 3/8lp now but I wonder if the sprocket is really 0.375... Guess I will find out

The Stihl Chain sprocket 3/8'' Picco 6T (P/N: 1120 640 2000, 11206402000) is the standard sprocket for the 011AV - https://www.diyspareparts.com/parts/stihl/chain-sprocket-1120-640-2000/
As the 6T is just slightly smaller in diameter than the 7T sprocket where the chain drivers engage, it delivers a slightly lower top speed of the chain and slightly more torque. Doubtful you will notice the difference, and if so you might actually prefer the 6T. I think it doesn't "bog-down" as easily when "working" the cut.
The largest member of the Stihl 1120 Series (009, 010, 011, 012) is the 012AV (with 2.8ci/45cc), and is usually only used with the 7T sprocket.

FYI, I run a 3/8 Picco 6T on my 011AV and MS200, and a 3/8 Picco 7T on my 012AV. They all use the same 55 drive link chains and 16" bars.

Here is a Stihl NewOldStock 3/8 Picco 6T for sale - https://www.ebay.com/itm/167185527416 for $14.50 with shipping.... Just sayin' ...

 

[Franny K]

I assume you are talking about the kit I linked to (that I just ordered)? Yeah, I'm not convinced it will work. I'm running 3/8lp now but I wonder if the sprocket is really 0.375... Guess I will find out

No it is not really .375 1640 drive links per 100 feet comes out to something like .367. If it is a generic small spline like I suspect you can run 9 tooth 1/4, and 7 tooth .325. The new mini .325 husky 21 and Oregon 80txl has the same dimension rivet center to sliding surface (unlike 3/8lp vs 3/8), essentially mini, NK, and normal choices in .325, so you have lots of experimentation available now. And then the 6 tooth spur mentioned above which may be available from Stihl.

 

[dwaugh]

No it is not really .375 1640 drive links per 100 feet comes out to something like .367. If it is a generic small spline like I suspect you can run 9 tooth 1/4, and 7 tooth .325. The new mini .325 husky 21 and Oregon 80txl has the same dimension rivet center to sliding surface (unlike 3/8lp vs 3/8), essentially mini, NK, and normal choices in .325, so you have lots of experimentation available now. And then the 6 tooth spur mentioned above which may be available from Stihl.

You lost me, I'm running 3/8lp now, you think the kit I ordered is not going to work?
Maybe I should also get the 6t version @Valpen mentioned just in case, I assume the adjuster will be able to take of the slack of a smaller gear.

 

[Valpen]

You lost me, I'm running 3/8lp now, you think the kit I ordered is not going to work?
Maybe I should also get the 6t version @Valpen mentioned just in case, I assume the adjuster will be able to take of the slack of a smaller gear.

Your post and this discussion regarding the 7T vs 6T sprocket got me wondering what was the original sprocket for the 011.
I just checked the original owner's manual for the 010 and 011, and the standard sprocket for these saws is the 6T.

And the adjuster will deal with the slack - I use the same 55 drive link chains and 16" bars on my 6T 011 and my 7T 012...

 

[dwaugh]

Your post and this discussion regarding the 7T vs 6T sprocket got me wondering what was the original sprocket for the 011.
I just checked the original owner's manual for the 010 and 011, and the standard sprocket for these saws is the 6T.

Thanks, that's good to know, the 7T was on it when I got it (used), so I just figured I would replace it with 7T without thinking about it, until I found out it was NLA. The saw gets light use, so I just need it to work right and I doubt the slight decrease in speed would bother me.

 

[dwaugh]

Got back from NJ and the new sprockets were here. I'm unsure if the rim sprocket on the left is really 3/8lp, the ebay listing says it should be, but from what arrived I'm not sure. The OD of the sprocket is 1.374" I know the 3/8lp should be larger in diameter than the regular 3/8 but I have nothing to compare it to. I'll probably just try the 6T on the right, as long as the chain still fits I'm sure I will be fine.

 

[dwaugh]

Well the 3/8 lp/Picco chain seems to fit the rim sprocket, but I still think it may be for regular 3/8 chain. The OD of the rim is 1.374" and the ID of the internal spline ignoring the grooves is around ~0.756" which I think makes is "small 7 spline". I'm just going with the spur sprocket, I've spent more than enough time trying to figure out if this correct Maybe @Franny K knowns

 

[Franny K]

Spend some more time. That 7 tooth drive will work ok and give more chain speed. Just be careful if you push the chain back and forth to check the tension. Might snag up a bit and get a small cut. Maybe by the time the cutters are used up there will be some abnormal denting on the drive links, maybe. I have one inboard clutch Stihl chainsaws and two of their pole saws so not familiar with the oiling drive of your model or if it oils at idle. The chances of the spur sprocket banging up the drive links on a derailing incident to the point it can't be field fixed are higher than the rim drive set up.

 

[dwaugh]

Spend some more time. That 7 tooth drive will work ok and give more chain speed. Just be careful if you push the chain back and forth to check the tension. Might snag up a bit and get a small cut. Maybe by the time the cutters are used up there will be some abnormal denting on the drive links, maybe. I have one inboard clutch Stihl chainsaws and two of their pole saws so not familiar with the oiling drive of your model or if it oils at idle. The chances of the spur sprocket banging up the drive links on a derailing incident to the point it can't be field fixed are higher than the rim drive set up.

Thanks! The 011 is a full time oiler and if you leave it idling it looks like you held up a steak in front of a hungry large dog

 

[Valpen]

Well the 3/8 lp/Picco chain seems to fit the rim sprocket, but I still think it may be for regular 3/8 chain. The OD of the rim is 1.374" and the ID of the internal spline ignoring the grooves is around ~0.756" which I think makes is "small 7 spline". I'm just going with the spur sprocket, I've spent more than enough time trying to figure out if this correct

I agree with your decision to go with the 6T spur sprocket, it is the OEM size and will bog down less than using the 7T rim sprocket (typically carving setups use 7T and 8T sprockets to increase chain speed and they are not interested in torque, just fewer cut marks).

If you want to dig further into the rim sprocket option, it looks good from what we can see in your picture.
But we can't see the actual contact surface of the drive links and the sprocket..., only the contact area at the outer rim with the chain links.
I would also reverse/swap the chain's orientation in the sprocket, as the chain is on backwards in the picture to see if it makes a difference.

You might gently secure the just the rim sprocket without the brake/clutch drum (in a vise or similar), and see if there is any slipage/movement if you pull back and forth on the chain while it is sitting in the rim grooves. I would expect it to fit snugly and have no "play", to indicate that the drivers are connecting with inner surfaces of the rim sprocket correctly.
If no play, you might give it a trial run and see what happens. And maybe pull the rim sprocket and look carefully down in the groove to see where the drivers are leaving their mark....
GOOD LUCK, and please share the results. You have a captive audience here....