Determining if a chainsaw spur sprocket is worn out.

Signs of a worn out spur sprocket on a chainsaw. Also the changing of a spur sprocket on a Stihl MS201T chainsaw. This applies to all chainsaws of all ages. As the chain wears it also wears the driver wether it is a spur sprocket or a rim sprocket. On the rim setup you can quickly and easily replace just the rim much cheaper than the whole clutch drum and spur assembly.

[@skhetan1]

Thank you for posting this. I’m getting that catching / clinking on the drum and suspected it was worn ! Will replace

[@brianmitchell535]

Thank you for posting this! It really helped me out. Mine was super grooved but it looked like a factory design until I seen you pull the new one out of the bag.

[@DugatDizzyLizzys]

Thank you for informing me about when the drive sprocket needs replacing. Still learning the answers I've seeked after 15 years 😁

[@ddfamf88]

Thank you - my Stihl sprocket looked and performed just like that! Time for new one!

[@Debtfreehomesteaders]

I miss my chainsaw... Very informational. Thanks for sharing! -Will

[@mrmojorisen6336]

good info and thanks for the tips. last year we had some big trees around our leeve cleared. cutting year old hardwood has been hell on my husky. problems been dry hardwood has been stopping up the oil ports in the bar. spur looks like the one on that stihl. ill be ordering a new one asap. thumbs up!!!

[@RMartin631]

There is a piston stop tool included with the drum. Remove the sparkplug, insert the tool into the cylinder and then rotate the engine until it bumps up against the piston stop. Then you're supposed to torque the clutch pack to 50nm. All of this is included in the Stihl Technical Reference Guide.

[@neilreid2298]

Really good info - thank you! While you have it apart, might be a good idea to put some high temp grease on the needle bearings. Just saw mine today- dry as a bone. Thanks for the vid!

[@NCSU4x4]

That is normal maintenace to give that bearing a small dab. Not too much or it will simply migrate to the clutch drum surface.

[@kevint8886]

i have a 201, this is VERY helpful, thanks much

[@valerijw4999]

Thanks the same problems was solved changing sprocket. I was suprised one day chain just stuck inside

[@ahmedm6041]

Thanks for sharing a valuable information!

[@swordfish1120]

Very good video. I mistakenly thought the V-grooves worn into my sprocket were supposed to be there 😝. My saw shows the worn signs that you pointed out in the beginning of your video. I'm going to order a new one today for my Stihl MS193T.

[@NCSU4x4]

Glad it helped you out. Many people do not realize a worn spur or sprocket can really affect performance and longevity.

[@swordfish1120]

@@NCSU4x4 When I checked my chains today, that I was recently using, I could see the signs of wear just starting on the links. Good thing I caught it in time. Thanks👍🏼

[@jhors7777]

Thank you for posting this helpful video

[@u.sonomabeach6528]

You actually pronounced the name correct. I don’t hear that too often. Pole-in ✅ I always hear people call them Poolin or powl-in.

[@unracker100]

Great info keep up the good work

[@DeathValleyDazed]

Thanks, you solved my question😎

[@BAKERHUSKIE]

Thanks for the video..

[@techronmattic5876]

Nice work

[@motomikebuilder]

I have a deep groove but it's not bottomed out yet.. Good advice,thanks.

[@michaelboyle1983]

Thanks, and God bless you!

[@alslitter1918]

Thank you for this video, I have a new saw which works with the existing bar and chain but I need a larger bar and chain for milling. I have tried several bars and chains but they jam just like you have shown here. I think the issue with the new chains is the existing sprocket but not sure. Can you or someone else help me???

[@NCSU4x4]

Think of a chain as a straight length. If you start out at a length of ~40 inches when new, when you add the wear of every bending joint, when your chain is "worn out" it has gained length. For an average 20" 3/8 pitch chain you could easily pick up 0.720" wear / gained length with only .005" wear per pivot pin on 72 drivers. Ok... so the chain drivers are now all more distant ... instead of being 0.375" between drivers you can change to 0.385" or greater. The spur drum or rim sprocket wears to accommodate this chain of pitch. When you install a new chain all of a sudden the driver spacing of the chain does not match the drum. Also add in the tops of the spur sprocket or rim sprocket decrease in diameter. This adds another changing dimension. I will try to do a video to show this. I think that is the easiest way to see and hear leading to understanding.

[@adamsmith6594]

@NCSU4x4 Can I ask. You took your sprocket straight off and it left the pin bearing behind. I've an old partner 370 with the same arrangement. Chain was dead, bar was overdue for replacement (25 years old) and the sprocket had some slight wear. But iv ordered an oregon replacement for that too. But when I got the sprocket off my pin bearing was tight inside the sprocket. I encouraged it free with a socket wrench socket and some gentle tapping. Seems all OK and freely runs. But should it be snug solid in sprocket or slide in and out. Yours appeared very free moving.

[@NCSU4x4]

Some of the older saws ran the roller bearing in a tight race in the drum. Newer saws run the setup you saw here. I'd gently push the bearing in the new drum, grease it, and never look back.

[@adamsmith6594]

@@NCSU4x4 I never got a notification of this reply. Damn you utube. Butni managed to source from onenplace a new sprocket with an integrated bearing. But, good to know that I could have gotten away with gently tapping the old bearing back into the new sprocket. Brilliant vid and response from the channel owner. Many thanks. Thumbs up.

[@alid8646]

As a newbie to the mechanics of a chainsaw. I'm.wondering how you determine the size of what spur sprocket you need. Are all spur sprocket run chainsaws the same size? The reason I ask as I want to change my 40cc chainsaw to a 1/4 pitch with a dime tip carving bar. Any help would be much appreciated

[@NCSU4x4]

Spur sprockets are pitch specific. You will need to consult with a parts list for your saw and see if it was available in 1/4" pitch. Most likely you will need an aftermarket drum which you may have to get through a carving supply vendor, likely the same one that is selling the dime tip bars.

[@alid8646]

@@NCSU4x4 thanks for the quick response. I realise the spur sprocket will need to be changed depending on the pitch of the chain. But are the housing (i.e. the metal cylinder connected to the spur (is that called the drum?)) the same width (circumference) for every chainsaw? Or do they vary? Hope that makes sense..😬

[@NCSU4x4]

@@alid8646 the clutch drum is specific to the saw or saw family. Some models such as the 021 / 023 / 025 / MS210 / MS230 / MS250 are all the same clutch and clutch drum bearing size. So for all arguments sake, clutch drums/spurs are saw specific.

[@jkgkjgkijk]

A lot covered here 👍

[@sunnyvishwakarma8474]

This is what you are applying new or how much money you have got

[@islandaerial3414]

Thanks! How much of a deal is the number of drivers on 3/8 picco chain? I have an old Homelite 245 that could use a new chain but, no one will touch up here on the Wet Coast of Canazuela I have see that an S59 is listed as a replacement

[@NCSU4x4]

The drivers is the measurement of chain length. If that is wrong the chain will be too long or short for your saw.

[@islandaerial3414]

@@NCSU4x4 Ahh, Excellent. Now I know. Thank you for that explanation. Much appreciated! 👍

[@terryhebb7967]

Should the sprocket have any play like side to side when its on ? or is it worn out ?

[@NCSU4x4]

Some side to side is acceptable. Generally when the clutch engages everything finds its "happy place"

[@brianmccutchan9513]

My dog's barking at yours.

[@TheTradesmanChannel]

Atta boy

[@chainsawsandgenerators9952]

did you check the gas? i would check the gas..

[@NCSU4x4]

Twice.

[@mongomay1]

Can a spur be converted to rim type?

[@NCSU4x4]

It depends on the saw. Some have an option and some do not. Some saws that do not have an option from the manufacturer do have the option through aftermarket companies such as Oregon.

[@gregmccarter2176]

Iv actually tig welded the spurs..only when I want to do it..other than that I just replace it

[@TruthHurts2u]

Stihl actually has a tool to measure the wear limit.

[@neilhamill318]

It's good you got the business / job. But a tree service company couldn't diagnose the problem. 😕

[@NCSU4x4]

They didn't realize it was a problem. Saw came to me for other issues and I found it as I was going through the saw..

[@neilhamill318]

@@NCSU4x4 That makes even worse. They never noticed it gradually getting more difficult to spin the chain freely each time the chain needed adjusting.

[@fishnriver]

Hold the sprocket still so it can focus!

[@jws3925]

Dud, this is good information but you need serious help with the camera.

[@NCSU4x4]

I appreciate it. Pushing pieces of equipment out takes priority over camera work... but I have looked at some different setups than a cell phone.

[@dontswin]

the poulan 42cc is not set up any thing like this. First I had no nuts (lol....my wifey still laughs about that) for the bar(2) the plastic cover would not fit flush. I bought a new 18" bar, chain, sharpener. Come to find out I got the saw running with nothing attached (bar, chain and shit)...the sprocket would NOT SPIN at all. Gas is good, lubRicant good why is the sprocket seized with nothing on the teeth. I may need this focking thing any night now,....I have tried for weeks to get this shit up and running....I may need it at a moments notice. It may end up in the focking trash.....I'm sick of it, I've been trying to figure this shit out for at least a month....I have no friends here into anything related to cutting branches or trees or whatever. Can you help? I'll send $.( just buy another saw and F it?...is that good?)

[@NCSU4x4]

Poulan setup is not terribly different. Same basic setup. The biggest difference is the bearing is captured in the clutch drum. Check the chain brake is releasing and not hung. Often the brake is left on, clutch slipped, and then the plastic surround melts to the band or melts in the way of the band keeping it from releasing. Check for deformed or dark colored plastic around the clutch drum.

[@dontswin]

@@NCSU4x4 Thx very much, I think I understand. I really think that's what happened inside there. I have to take the tiny O ring off and take a look inside. Is it fixable or buy another saw? Thank you.

[@NCSU4x4]

@@dontswin generally those saws are not worth the effort to repair. I saw a report years ago the designed life span of them was less than 15hrs. For most light home owner use, thats more than 15 years of trimming tree limbs and miscellaneous small tasks. If you get to using them for firewood or other continuous duty tasks they quickly fail. I generally suggest looking for a better quality saw for that type of work.

[@dontswin]

@@NCSU4x4 I'm fairly certain something to do with the clutch brake plastic pc. inside there melted causing it to seize, like you said. I don't know if I take it apart have the skills to get what I need and get it back together again. I already spent $50, lol. THX , for all your help. I guess I should find another saw.🤔🤯

[@crxess]

Title is completely wrong. this had nothing to do with Determining if the Spur sprocket is worn out. in fact you didn't even show the Spur Sprocket.