Stihl 041 AV won’t “accelerate”

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Was there issues prior the rebuild ?? How Mild?

Yes there were issues prior to the rebuild/refresh that I did. This same acceleration issue was present and the saw just plain wouldn’t perform consistently at all. Now the saw is consistent but the “acceleration” issue as I’m calling it is still happening.
 
Just my comment about timing/advance.

You may have play in your key or if it is electronic, the trigger plate may need to be rotated slightly.

They key I know how to check no problem. How would I go about checking the timing/advance & trigger plate?
 
It depends which type you have, but they all have some play where they bolt down.

The 041 has 2 different types of electronic ignition, you will have to determine or recall which type.

Do you have the service manual for your saw?
 
Not sure if it is the same as mine or not. Crooked scans?

It covers both electronic types if it is.
 
Looks like multiple issues there.

The engine doesn’t sound great, but regardless, the chain should be moving more for the rpm that engine is turning.

My bet is a clutch issue. Either the brake is on, something is dragging, or the clutch just isn’t grabbing the drum to spin it.

Has this happen with an 044 I bought as a “runner”. Finished porting the saw and I kept noticing how easy it was to remove the clutch. In the end, the center section of the clutch was cracked in 2 places and would open up and skip over the threads at load. The saw would idle and rev perfectly, but not turn the chain.
 
Oh what the heck I'll get in on this one . I'll agree that engine doesn't sound good but it should do better than that regardless of a bad clutch ,ignition problem or a bad carb. The saw started on the second pull unless it was previously warmed up for the video. If the saw had an ignition timing problem it would show up before it fired and be hard to start. The carb kind of sounds like the high speed side is lacking or plugged up, restricted in some way.

Something is binding and holding back the chain speed. See what happens without the bar and chain. I'd start there and work backwards. Other than the chain brake being engaged how about the nose sprocket in the tip of the bar being half way seized or clogged with dirt and sawdust. The bar rails clogged with sawdust and dirt or overly tight due to mismatched chain and bar combo or worse and rare is wrong chain pitch and drive sprocket combo or a slightly bent bar.
 
I'm not real familiar with that "chain brake with isolating clutch" setup.

Maybe someone that has dealt with it will chime in.

If I recall, the brake has a shoe to stop the drum and also a lever that trips the sliding section of the clutch. There should be a spring that returns the slide and locks the clutch together. Check for movement there. Best solution, get rid of that isolating clutch.

Chris B.
 
Just wrapped up the job I’ve been out of town on, assuming there’s no fires to put out when I get home then I’ll get fresh pics tonight. Worst case scenario I’ll get them when I wake up tomorrow. Thanks for all the input fells
 
Made it home finally, then slept for most of the 1st 24 hours I was back. Then instead of doing the right thing and or responsible thing like finishing up this chainsaw “rebuild” I started an embarrassingly long time ago.......

I decided to feed the beast within and brought this gem home :happybanana:


7CE71B89-FE9D-4185-942E-6B7E6D08B832.jpeg 5A75BCD6-B7F4-407C-ADA4-FA055B54366D.jpeg

And now that my parts order for it is finally placed & its 5am so little chance of being bothered. I swear I’m walking out to the garage right after i hit post!!!







Promise......:innocent:
 
Better late than never right??







Wrong... late is late 9 times out of 10 ;)


So without further ado

D918B29A-7F08-498D-8EE2-FB8C2EAD8640.jpeg 95F4C07E-B6A2-4384-8B41-18ED28C07B9A.jpeg 22BC74FA-0920-4B32-A28F-320696935AB1.jpeg 712361E2-5F37-4803-82F6-5B06EC2B847F.jpeg 54042DF2-9AD0-4991-A4DA-6DD004FE56AF.jpeg 0843F4EB-E0AF-435C-9A99-6870AD6DF6DC.jpeg

Here are just some pictures of the clutch assembly in case anybody happens to see something I didn’t. I’m going to read back through the comments and see if I can identify some other picture requests and get those taken and posted here shortly.
 
Oh what the heck I'll get in on this one . I'll agree that engine doesn't sound good but it should do better than that regardless of a bad clutch ,ignition problem or a bad carb. The saw started on the second pull unless it was previously warmed up for the video. If the saw had an ignition timing problem it would show up before it fired and be hard to start. The carb kind of sounds like the high speed side is lacking or plugged up, restricted in some way.

Something is binding and holding back the chain speed. See what happens without the bar and chain. I'd start there and work backwards. Other than the chain brake being engaged how about the nose sprocket in the tip of the bar being half way seized or clogged with dirt and sawdust. The bar rails clogged with sawdust and dirt or overly tight due to mismatched chain and bar combo or worse and rare is wrong chain pitch and drive sprocket combo or a slightly bent bar.


To touch on a few of the points you made and respond to a couple of the questions you had:
- The sprocket at the nose of the bar spins freely and the grooves that the chain rides in on the bar are clean and oiled
- The chain brake is not on, I double and then triple checked just to make sure. Cus that would be some stupid **** I would manage to pull off....
- The bar is straight and true according to my middle Street age/ruler
- this song was just recently cleaned and freed have any debris’s and sawdust I could manage to blast off of it just prior to rebuilding the carburetor
- I will post a video of me starting the saw without the B/C on and we’ll see what happens
- in the first video I posted I had not previously warmed up the saw before that video
 
529A71BB-9F39-4751-A1FA-758B3A3D17F0.jpeg
If I recall, the brake has a shoe to stop the drum and also a lever that trips the sliding section of the clutch. There should be a spring that returns the slide and locks the clutch together. Check for movement there. Best solution, get rid of that isolating clutch.

Chris B.

I believe this picture should show the shoe and spring you brought up in your post
 
Back
Top