Stihl 066 problem(s)

[Stihl dude]

Hello to all. New to chainsaws
I have a Stihl 066 that I freshly serviced at a dealer. Everything checked out. Brought it back home and starting cutting some logs.
started well, went full throttle, no loss of power while cutting. However, it loses power (shuts down) while idling.

Things I know are working:
-Carburetor is dialled in
-Using Stihl 50:1 pre mix
-Starts first try no problem
-Piston is not scared

Things I’ve noticed:
-Compression seems a little low (not tested). If I lay the saw on the ground there is little resistance
-When pulling on cord, I here air sounds (pffffff pffffff)

What do you think could cause this problem?
What parts should I check? What should I replace?

Thanks for the help!!

 

[bulletpruf]

If your saw dies while idling, your carburetor likely isn't dialed in. It may need the low-speed jet adjusted and/or idle speed adjusted. Easy enough to do; I could try to explain it here, but you're better off checking out a youtube video.

I always do a compression check on my saws when they first arrive. That's good info to have.

That noise you hear at idle may be the compression release leaking. Not uncommon.

 

[Stihl dude]

If your saw dies while idling, your carburetor likely isn't dialed in. It may need the low-speed jet adjusted and/or idle speed adjusted. Easy enough to do; I could try to explain it here, but you're better off checking out a youtube video.

I always do a compression check on my saws when they first arrive. That's good info to have.

That noise you hear at idle may be the compression release leaking. Not uncommon.

I’ll look into dialling the carb thank you!
Just ordered a compression testor as well.
Is the compression release leaking something I need to fix ?
Also, do you think it could use a top end rebuild or should I wait until it stops working?
Thank you

 

[bulletpruf]

Tuning the carb will likely fix your idling issue.

The compression test will tell you if you're leaking too much out of the valve.

 

[Vintage Engine Repairs]

could be main nozzel not sealing and sucking air at idle, but more likely it’s a tuning issue.

 

[Vintage Engine Repairs]

Tuning the carb will likely fix your idling issue.

The compression test will tell you if you're leaking too much out of the valve.

Out of the valve?!

 

[Bob Hedgecutter]

Out of the valve?!

Yes Tommy- the decompression valve.

 

[Vintage Engine Repairs]

Yes Tommy- the decompression valve.

Ahhh gotcha

 

[Maintenance supervisor]

Yup, sounds like the decomp is stuck open.

 

[ZeroJunk]

Yup, sounds like the decomp is stuck open.

I had two MS261's given to me a few weeks ago . One had a scored piston sure enough which I replaced. On the other the piston looked fine. You could hear the air going out the supposedly closed decomp just turning by hand with the flywheel. New decomp valve and it runs fine.

 

[DND 9000]

I have a Stihl 066 that I freshly serviced at a dealer.

That is the answer. Go back to the dealer who messed with it. He should make it right, normally there is a warranty that if it goes back to the customer it has to work properly.

 

[Canyon Angler]

You can probably put a plug into where the decomp valve threads in. That's the way my 660 was built.

Seems like my 361 wants to flood every time I use the decomp, so I don't use it anymore.