Stihl 066 chainsaw problem

[Mr. Firewood]

I have a older (4yrs old) 066 saw and it dosent like to run when it gets colder then 20 degrees outside, i have ajusted the jets and tried different grade fuels and synthetic oils and nothing helps it,I hae run out of ideas, any help is welcome, thanks Nate

 

[BIG D]

Well, its hard to diagnose a saw over the net, but how lean do you have it adjusted. When the saw is cold it will need quite a bit more juice to get it started. I was also thinking it had a little water in the gas also. It could be poor diaphrams in the carb also. They might be stiffening up. Just a few thoughts.

 

[Chainsaw]

066 problem

I think I know what your problem is.
I work in a Stihl Dealership in Central Illinois and I have seen this before
I think that the carburetor is iceing up after you run the saw for a while. There is a couple of things that you can do to help keep this from happening. The first is that you should have a cold temp setting on that saw. This is usually a small piece of black plastic that can be turned around in cold weather to allow warm air from the saw to warm the carb. It will be most likely be located in the air filter cover. The second thing that you can do is to install a shield kit for the cooling holes on the rope starter side. This helps a lot if you cant find one of these kits let me know and I will sell one to you. As far as the carburetor adjustment goes take it to your local Stihl dealer and have them set it with the tach. You can get close by adjusting it one turn out from when it lightly touches but with that expensive of a saw spend a few dollars and have a Professional set it for you it will be worth it. I have seen more than one saw that was destroyed by messing with the adjustments. The ONLY oil that you should be using in the mix for that saw is the Stihl mix. And there is a difference in mix oil and NEVER use synthetic. If you really want to know why let me know and I will explain. Hope this helps you if not let me know.

 

[Deere John]

OK Mr. Chainsaw - I'll bite. I have a small fleet of Stihl saws, from 026 to 066, and I have always used commonly-available 2-cycle oil in them, though not synthetic.

Please detail the reasons to use Stihl oil - I'm interested to know.

 

[Chainsaw]

why not synthetic

There is a simple answer to that question. If you look at the cylinder walls of a Stihl cylinder under a microscope you will see that there is tiny pores in it. They are there to hold a small amount of oil on the cylinder wall in the event that there isn't quite enough oil in the mix. If you use a synthetic oil in a Stihl product the plasticizers in the oil will plug up the pores. Then the oil cannot get in or out to do you any good. If you don't believe me take a Stihl cylinder that has been run for awhile and clean it out good with brake cleaner sprayed on a shop towel. Let the cylinder sit for a week or two and I will bet that there will be oil in the bottom of the cylinder that has seeped out of the pores. If you have ever run synthetic oil in it this will not happen. Try it I have and it works.

 

[Chainsaw]

Stihl oil

Also if you read your owners manual you will see that there is a different mix recomendation for non Stihl oil. When you are spending that much on a saw why not use what is recommended in it. I have seen proof that some oils can cause carburetors to plug, Exhaust screens to plug, and tar on the piston, cyl and rings.

 

[Mr. Firewood]

thanks guys

it was the diaphram in the carb, it was verry stiff, I replaced it and messed with the jetting and it runs like a champ

 

[thomas1]

I recently purchased some synthetic oil, should I dump it down the storm drain?

 

[Sprintcar]

I recently purchased some synthetic oil, should I dump it down the storm drain?

Ditto, 16 years of running from an 019 to an 084 with nothing but syn mix, must be doing somethin wong.

 

[mitch95100]

I can tell where this is going... c ya!

Sent from me to you using my fingers

 

[nixon]

I recently purchased some synthetic oil, should I dump it down the storm drain?

Don't know the answer to that one Thomas. I'm still trying to figure out how to get a micro scope into the jug of a saw !

 

[John R]

Ditto, 16 years of running from an 019 to an 084 with nothing but syn mix, must be doing somethin wong.

Man, your going to plug your pores. :msp_biggrin: :msp_biggrin:

 

[John R]

I recently purchased some synthetic oil, should I dump it down the storm drain?

Send it to me for proper disposal. :hmm3grin2orange:

 

[thomas1]

Send it to me for proper disposal. :hmm3grin2orange:

Do you live in the storm drain?

 

[Fifelaker]

Don't know the answer to that one Thomas. I'm still trying to figure out how to get a micro scope into the jug of a saw !

Look through the big end of binoculars at the microscope and it will fit inside a cheerio.

 

[old-cat]

That synthetic stuff must be pretty bad! I guess that's why STIHL gives a longer warranty when you buy it with your new STIHL power equipment????

 

[thomas1]

Look through the big end of binoculars at the microscope and it will fit inside a cheerio.

What does this have to do with plasticizers?

 

[KenJax Tree]

Do you realize this thread is 12 years old?

 

[XSKIER]

Do you realize this thread is 12 years old?

So what? A good oil thread is timeless!

 

[nixon]

Okay , having thought this through completely ....... The man may have had a point about synthetic . If as claimed the cylinder was full of tiny holes , wouldn't the super slippery syn oil get out too quickly causing extreme friction and letting all that compression stuff out in the bargain ? It's just a working theory , so don't judge !