Stihl 23 Chainsaw won't Start

[GrumpyPants]

Hi, I'm new to Arborist. Been wrestling with this Stihl 023 chainsaw for way too long -- helping out a friend -- it belonged to her late husband. Below is a list of what I did. At this point, I suspect the issue is with the ignition coil, or perhaps worth trying Stihl oil, or fuel mix (instead of the cheapo oil I bought at Walmart which works fine with my Echo equipment). Appreciate any suggestions on how to narrow this down further.

0 - Stihl 023 Chainsaw would not Start (hasn't been used in ~20 years). Difficult to pull flywheel/cord. Removed spark plug, gave it a few pulls. Adjusted Spark plug gap and reinstalled. Would now Start but would not Run.
1 - Changed spark plug -- start but would not run. Would flood. Gas dripping out near the muffler area.
2 - Cleaned carb -- bath in Simple Green. Added more gas to the mix as I saw there was a lot of oil residue on the spark plug. Got it to Start and then Run with full throttle but unit would not idle and would eventually die.
3 - Repeated 2, tried adjusting carburetor and eventually reset to 1 full turn counter-clockwise on Low speed adjustment, same result as 2. Initially, the Low Speed was set closer to 2 turns.
4 - Checked spark arrester, it's clean
5 - Checked piston (visual inspection from exhaust side). Looks real smooth, compression also "seemed" good when pulling the cord.
6 - Changed fuel (perhaps this is more finicky than my Echo equipment). Bought new gas added 50:1 oil mix (back to ratio prior to change in 2 where I had more oil mix). Start, Run but no Idle.
7 - Changed fuel line (noticed it was damaged -- I believe I did this when doing 2). After changing fuel line, would no longer Start or Run.
8 - Changed carburetor (it's not an OEM but has good reviews). Tried adjusting carb and eventually went back to 1 full turn counter-clockwise on Low speed adjustment. Never Started.
9 - Checked spark with plug grounded wire. Did not see Spark. Adjusted air gap in ignition coil with a business card. See white/yellow spark but still won't Start. (Spark too low -- should be blue?)
10 - Checked impulse line. It's hard to get to, does not seem damaged -- not sure it's worth the effort to replace since plug is wet with oil residue.
11- checked compression, I got 135 PSI which appears to be within spec.

 

[nighthunter]

Sounds to me to be a bad coil

 

[mgr]

Bad coil.

 

[Conquistador3]

Hi and welcome.

A Chinese coil is about $10 shipped on eBay. Even if you don't want to use it long term it's a great and dirt cheap tool to diagnose a bad coil.

 

[Woody Longbranch]

Clean the embedded magnet portion of the flywheel with sandpaper and the pick-up porton of the coil. Could be too much corrosion on either or both components to allow the spark to be created, especially after 20 years of sitting

 

[TheTone]

The saw had more than one problem - carb and probably coil. Since it has been sitting for 20 years, I would also want to check the condition of seals and impulse line with crankcase P&V test.

 

[GrumpyPants]

Per Woody Longbranch's suggestion, I cleaned the magnet portion of the flywheel and pick-up port of the coil with sandpaper and she fired right up. However, it only runs when I have it on full throttle. It stops soon after I let go of the throttle and won't run on idle. I turned turning the low speed adjustment on the carburetor slightly counter clockwise but it seemed to make starting more difficult. I basically back to step 2. Perhaps the coil is not good enough to run on low speed/idle? I have no problem ordering one -- just wondering whether this is more likely a carburetor adjustment issue, or if there are other things I should try.

 

[Woody Longbranch]

If you get a spark and it fireds up you got spark the coil is working.
now you dealing with a fuel / carb air intake problem
On the bottom of the carb is a removable plate .take it off and check the diaphragm ,4 little screws holds the plate over the fiber and plastic membrane which acts ad the "fuel pump"out of the carburetor and see if it's brittle than thats another problem
douche the carburetor really really good with carburetor cleaner squirted in all the little holes

 

[Andyshine77]

Did you try rebuilding the oem carb? The aftermarket carbs are hit and miss and even good ones can be fickle to tune. A saw that's been sitting that long will often need to be gone through. This is likely still a fuel related issue however. Try lightly seating the L and H needles, than back them out 1.25 to 2.5 turns, than see if this video helps you out any.



Sent from my LG-H871 using Tapatalk

 

[GrumpyPants]

Thanks Woody, I'm happy to do that to rule that out again. However, this is a new carburetor. I did dismantle the old carburetor and checked the diaphragm and membrane when I performed step 2. It looked good to me -- not too brittle. Behavior is the same with old and new carburetor.

One thing I noticed. The master control has 4 positions: 1- Cold Start, 2- Warm Start, 3- Run and 4- Stop. I usually start on 1- Cold Start, get a little spark after a few pulls and it stalls. I then move it to 2- Warm Start where it starts and runs on idle after a few pulls. After I press the throttle the control moves to 3- Run. However, it can't stay running in idle when in 3 even though it does initially when in 2. So, it won't idle when the choke is totally off. Does that tells us anything?

 

[Woody Longbranch]

Sorry I missed that you replace the carburetor but now I remember you did sounds like it's starving for fuel usually putting the choke on and that makes it run usually means it's a starving for fuel you say you changed the fuel line you changed the fuel filter. Not familiar with that model saw but it doesn't sound like the coil to me sounds like a fuel or air problem. , the fact that it runs and has good compression tells me that . I have seen where the main bearings I want out and that if you grab the flywheel portion of the engine and wiggle it up and down and there's a lot of play then it'll run for a little while but when it gets out of orbit it it like binds up and won't stay running wiggle wiggle the flywheel with the pull starter off grab the flywheel and push it up and down and see if it's sloppy see if it's sloppy

 

[walterg]

Did you change fuel filter? I don't see where it's mentioned.
If you used an AM fuel line it might be kinked causing fuel restriction.
Also if you did change fuel filter an used an AM one, some of them are garbage.

Sent from my LGLS775 using Tapatalk

 

[Andyshine77]

Thanks Woody, I'm happy to do that to rule that out again. However, this is a new carburetor. I did dismantle the old carburetor and checked the diaphragm and membrane when I performed step 2. It looked good to me -- not too brittle. Behavior is the same with old and new carburetor.

One thing I noticed. The master control has 4 positions: 1- Cold Start, 2- Warm Start, 3- Run and 4- Stop. I usually start on 1- Cold Start, get a little spark after a few pulls and it stalls. I then move it to 2- Warm Start where it starts and runs on idle after a few pulls. After I press the throttle the control moves to 3- Run. However, it can't stay running in idle when in 3 even though it does initially when in 2. So, it won't idle when the choke is totally off. Does that tells us anything?

Try turning in the LA screw two or three turns, see if that works. If it idles too fast just back it out some. I think these guys are getting you a bit confused about what's going on. Take things one step at a time. I would really prefer you use the oem carb with a rebuild kit, the no name carbs are almost always garbage.

Sent from my LG-H871 using Tapatalk

 

[Knobby57]

If it runs wide open the fuel filter probably isn’t holding back the fuel but I would change . Make sure the rubber parts arnt cracked and or leaking . I little air leak will be the death of the saw fast . Intake boot . Fuel line and impulse line . I would get these from a dealer ... that old I would be throwing seals in also .

 

[GrumpyPants]

Actually, no, I didn't change the fuel filter -- just the fuel line. I'll go pick one up -- who knows what 20 years sitting the in the tank might have done.

Sorry I missed that you replace the carburetor but now I remember you did sounds like it's starving for fuel usually putting the choke on and that makes it run usually means it's a starving for fuel you say you changed the fuel line you changed the fuel filter. Not familiar with that model saw but it doesn't sound like the coil to me sounds like a fuel or air problem. , the fact that it runs and has good compression tells me that . I have seen where the main bearings I want out and that if you grab the flywheel portion of the engine and wiggle it up and down and there's a lot of play then it'll run for a little while but when it gets out of orbit it it like binds up and won't stay running wiggle wiggle the flywheel with the pull starter off grab the flywheel and push it up and down and see if it's sloppy see if it's sloppy[/QUOT

Did you change fuel filter? I don't see where it's mentioned.
If you used an AM fuel line it might be kinked causing fuel restriction.
Also if you did change fuel filter an used an AM one, some of them are garbage.

Sent from my LGLS775 using Tapatalk

Correct, I had not changed the fuel filter -- only fuel line. I just picked one up and changed it. No difference.

 

[GrumpyPants]

Try turning in the LA screw two or three turns, see if that works. If it idles too fast just back it out some. I think these guys are getting you a bit confused about what's going on. Take things one step at a time. I would really prefer you use the oem carb with a rebuild kit, the no name carbs are almost always garbage.

Sent from my LG-H871 using Tapatalk

I tried turning the LA clockwise to increase the idle. It didn't help. Unit would surge on Warm Start and then stall. I have the H and L set to one turn from the seated position. I have tried setting L to 1.5 to 2.5 turns but this does not help -- it gets worse.

 

[GrumpyPants]

Did you try rebuilding the oem carb? The aftermarket carbs are hit and miss and even good ones can be fickle to tune. A saw that's been sitting that long will often need to be gone through. This is likely still a fuel related issue however. Try lightly seating the L and H needles, than back them out 1.25 to 2.5 turns, than see if this video helps you out any.



Sent from my LG-H871 using Tapatalk

Thanks, I've looked similar videos several weeks ago. Unfortunately, I could never get my unit to idle long enough to set any of these screws while running and any change would often result in making the start more difficult.

 

[GrumpyPants]

If it runs wide open the fuel filter probably isn’t holding back the fuel but I would change . Make sure the rubber parts arnt cracked and or leaking . I little air leak will be the death of the saw fast . Intake boot . Fuel line and impulse line . I would get these from a dealer ... that old I would be throwing seals in also .

Impulse line is hard to get to on this unit. Visually I did not find any cracks. I could change all that but at this point, if I have to buy parts from the dealer I might as well have them inspect it and recommend the fix. Would be $30 well spent given what they charged me for a fuel line and filter. I think I spent enough time on this. I'm about to throw in the towel.

 

[GrumpyPants]

Thanks, I've looked similar videos several weeks ago. Unfortunately, I could never get my unit to idle long enough to set any of these screws while running and any change would often result in making the start more difficult.

Also, I did look into rebuilding the OEM carb. The dealer discouraged me from it and suggested I buy a new carb instead. Obviously we were talking about OEM at the time.

 

[Knobby57]

Most dealers won’t rebuild carbs anymore . They rather just throw a new carb on . Just me I’ll try. A 7$ kit before dropping 75-100 on a new factory carb