023 Stihl ?

[flh69]

I cannot get the saw to idol without the chain spinning. Tried replacing the clutch springs but that did not help. I've tweaked the carb numerous times but still the same. It starts & runs great, idols down great but to get the chain to stop spinning at idol it shuts off??????

 

[HarleyT]

Take off the sprocket and take a peek,

see if it isn't something simple.

 

[flh69]

Take off the sprocket and take a peek,

see if it isn't something simple.

I did remove the sprocket as I thought maybe a spring had left loose. I did not see anything abnormal. This is my boy's saw. He got it from the original owner and was told the saw has always done this. I wonder if the drum may be a little undersize or if the weights are oversize??

 

[irhunter]

I've tweaked the carb numerous times

I would suggest:

1. Post pics of clutch and drum.
2. Set both H and L back to factory settings. Report back.

Roy

 

[chainsaw-57]

Check bronze bushing in worm gear. Sometimes they move and cause the drum to turn.

Larry HOS

 

[flh69]

I would suggest:

1. Post pics of clutch and drum.
2. Set both H and L back to factory settings. Report back.

Roy

Check bronze bushing in worm gear. Sometimes they move and cause the drum to turn.

Larry HOS

My son picked the saw up last night. He is bringing it back over & I will take another look at it. I'll let you know. Thanks for thanks for the replies.

 

[HarleyT]

Put up pics when you get it.

 

[user 74409]

If prior owner ran saw with dull chain the crankcase seal behind the clutch may have overheated and partially melted. Damaged crankshaft seal will cause an air leak and cause the saw to run lean and idle too fast (fast enough to engage clutch). To test, start saw and let it warm up briefly. With clutch cover removed, take can of brake cleaner with thin red straw and give healthy spray toward area behind clutch (keep spray away from air filter area). If engine stops or changes speed, you have a leaking crankshaft seal. Seals are not expensive but saw will need to be mostly disassembled to install new seals and crankcase needs to be resealed with gas resistant sealer (Motoseal, Dirko, Threebond 1184, etc.). Common issue with 021/023/025/MS210/MS230/MS250 models.

 

[Ironhorsedoctor]

I agree with craigmn Sounds like a vacuum leak! It’s definitely worth the effort and disassembly of the saw! It’s not actually a difficult job and it allows a chance to do an overdue cleanup of the chassis and related parts. The IPL shows two different part numbers for the crankshaft seals. One part number is for replacing the seal without removal of the engine pan/ sump and the other part number is if the engine pan/sump is separated. I would suggest getting the seal for when the pan/sump is separated. It’s a twofer! New seals and resealing the pan. As craigmn mentioned you will need a gas resistant sealer for the pan/sump. l use Dirko ( Stihl brand ) and I always use OEM seals. This is also a good time to replace the impulse hose and fuel line and filter. If I remember correctly the cheaper of the two seals is the seal that you want. The other seal has a metal outside ring to aid in pressing the seal in. I’ve always separated the pan!
Separating the pan also allows you to inspect the crank and rod bearings!

 

[ballisticdoughnut]

The 021, 023, and 025 saws can develop an air leak where the bottom portion of the engine is bolted to the cylinder. If that’s the case it will have to be completely torn down. Same goes for crank seals. Check the oil pump drive gear and clutch bearing as well. Those would be the easiest things to check first.

 

[SteveSr]

Seals are not expensive but saw will need to be mostly disassembled to install new seals and crankcase needs to be resealed with gas resistant sealer (Motoseal, Dirko, Threebond 1184, etc.).

Do NOT use Motoseal on these engines. It is not rated for gap filling and does not harden. Don't ask me how I know!

 

[Ironhorsedoctor]

Do NOT use Motoseal on these engines. It is not rated for gap filling and does not harden. Don't ask me how I know!

Good to know! Thanks! As I mentioned before I always use Dirko. I got it awhile back from my local Stihl dealer.
One tube will last you through quite a few overhauls or reseals!

 

[flh69]

I have not ruled out a leak but I do have another question? Does the chain brake have any control of the slowing down the chain speed when coming back to an idol?

 

[user 74409]

Chain brake has no effect slowing chain in normal operation. Think of brake as an on-off switch. With brake handle engaged metal band around clutch drum is tightened to grab outside of clutch drum. With brake off there is an air gap between metal band and clutch drum.

Chain slowing to stop is controlled by clutch engagement. When engine speed drops below clutch/chain engagement speed the engine stops turning chain. If saw is idling at or above clutch/chain engagement speed the chain will keep spinning. See below for old posting with clutch/chain engagement speed examples. Stihl 023 rated idle speed is 2,800 rpm as a reference.