High hr Stihl 066

[rogue60]

Thought some might find this interesting.
I've kinda been looking forward to this day as I have never been inside this saw, on the conservative side one thousand plus hrs but could be as much as two thousand hrs on this saw put it this way hell of alot of hard working hrs.. Its not had an easy life. for a couple of years I do remember it didn't just breathe fines as all saw's do, the filter lip was trashed and it breathed chips and chunks of hardwood! (see pics).
It's always been a strong running saw up until a few days ago its been running erratically hard to start and to me not looking to far into it seems like carby or air leak? as its seems to be running very lean could even be impulse line I don't know as yet.
I will go through it and find whats up but for now was just happy I finally get a look inside this very high hr old 066 owned from new..
Not all is original I know I have replaced many parts over the years rear tank ,top handle a few times clutches/ clutch covers/ top covers, basically cases have never been split or the jug /muff has never been off not sure if carby is original..
Few pics- I was surprised at what I found and I put that down to the oil run in this saw its hole life and strange considering all the myths getting around the internet about mineral 2T oil?..



This is the saw in 2009 it was old even back then and the crap it was eating. I used to think this saw will die any day but bugger me it just keep going and going year after year ...

 

[rogue60]

Today pulled it down- looking at the inside muff pics looks like its been hot? but as I said since its been playing up seemed to be running lean I would have run it tell it blew up but in the end it would only rev up a bit and then die..

 

[rogue60]

Now the interesting pics looks really good inside no carboned up exhaust port? rings still look to be sealing really well and not what I'd call high bad ware on the load side of piston skirt? ,sure there is ware as you can see but dam looks good to me for such a high hr saw, don't get me wrong it's worn out but it did make it this far without a major failure. I will get it going again and who knows how many more years it will run might only last a day or not .. Only thing I find odd piston has carbon but combustion chamber is relatively clean what up with that is that normal? saw has been run on Castrol Active mineral oil at 25:1 and of course tuned to this mix ie runs strong/does not blow smoke think I'll continue using this cheap oil I cant see anything undue that could be blamed on the oil myself...

No rhyme or reason to this just interesting viewing of a high hr saw run on the wrong oil and mix and a life of ingesting fines and slightly larger chunks of wood.

 

[rogue60]

Carbon is just kissing the squish band had it at TDC when I wiggled the jug off that's the rub marks you can see on the squish band...

 

[drf256]

Thanks for posting. It's a testament to how tough Stihls are (and chainsaws in general).

I'd put that jug back on and clean that saw more before any more disassembly. Unless you plan to split the case.

Why a decomp if an 066? Is that an AM jug?

 

[CR888]

No varnish on piston what so ever, you would not get that running synthetics that long. I run Shell advance SX mineral 2T oil and have similar looking pistons. Are you going to give this saw some love... bearings, seals, intake boot, rings, carb kit etc? Damn tough saws them sic sixes!

 

[Brewz]

Great stuff!

It sounds like an air leak.
usually intake boot or crank seals

If it were mine, I would pull it right down, split the case, clean it out, new bearings, crank seals and all new rubber throughout.
The farmertec complete 066 rubber kits are fantastic and cost less than 1 x OEM av mount.
Carb kit, new cabers, tune and run it for another 2000 hours!

 

[rogue60]

Thanks for posting. It's a testament to how tough Stihls are (and chainsaws in general).

I'd put that jug back on and clean that saw more before any more disassembly. Unless you plan to split the case.

Why a decomp if an 066? Is that an AM jug?

Decomp? I don't know that's how I bought it new from the Stihl dealer, myself I've never owned a really old 066 without a decomp, its an Aussie 066 as you can see I've never used the deomp but yes it has one does it work I don't know? lol...
Here's a few numbers off it.. As for age hard for me to say got so many of em but maybe 13 + years old or more? I know its the last one I got still going with the small oil tank and that bung thingy near the oil tank (bung has fell out)..

 

[bennne]

That's a late 066 before they became the ms660 that's why it's got a deco

 

[rogue60]

CR888 no love for this saw yeah I know poor thing haha.. I will only replace any parts it needs with parts off parts saws so no new parts for this old girl ..
It has me intrigued just how long can I get out of the bloody thing..
And your right about some of the oils run and pics put up with only like 3 gallons run time and they look like chit for real! ,this saw has had a thousand or so of tanks of fuel put through it running the same nasty mineral oil lol...

Brewz I don't think its intake boot had a few with a rip over the years and symptoms don't match past experience but ya never know, my gut feeling is it's just carby mesh blocked?.. I should get time over the weekend to have a better look at it, today I was just happy pulling chit apart its been awhile haha...

 

[bennne]

By that serial number it is one from just after they revised the 066 so it's got the bigger big end and m10 nut, round covers and modified inlet manifold but the small oil tank and std out put pump

 

[Brewz]

Rogue, what oil have you been using?

 

[rogue60]

Rogue, what oil have you been using?

How many beers you had Brewz? lol, I said back up near the top what oil was run in this saw? best to get on ya pushie Brewz and go looking haha....

 

[Hinerman]

Rogue, what oil have you been using?

Castrol Active mineral oil at 25:1.....see post #3

I am assuming this:

http://www.castrol.com/en_us/united...ke-engine-oil/2t-2-stroke-motorcycle-oil.html

 

[Brewz]

How many beers you had Brewz? lol, I said back up near the top what oil was run in this saw? best to get on ya pushie Brewz and go looking haha....

Ahhh was so busy looking at the pictures I missed what you wrote.
Kinda like a penthouse magazine

 

[smokey7]

It sure looks really good internally. I'd be very happy to have one with that many hours on it with such a clean topend. I don't know if I can get that oil here but @ 25:1 it's burning very good. Now as far as the starting issues you are dealing with sounds like a carb issue or a impulse issue. A little testing will tell you forsure. Also I cringe at the dirty saw with the top end pulled...... it makes it so hard to keep that crap outta the case with it so dirty. At minimum blow it off with compressor before opening it up. Very nice saw, keep it going .

 

[Brewz]

Na will be this one

http://www.supercheapauto.com.au/on...cle-Oil-1-Litre.aspx?pid=1105#Recommendations

 

[rogue60]

This stuff-I was poor as a kid and could never afford the good synthetic oils like my mates run in there mx bikes but I had good results with this oil in bikes and moved into using it in saws and that was well over 20 years ago, have experimented with sinthetics in saws but didn't like what I seen.
In no way am I saying this is the best oil just it has worked for me in work saws, ported and or race saws may need a better oil I don't know? all I know is I've not found the limit to this oil in my saws at this point in time...To me even an 088 only puts bugger all load like 5% off what a CR500 can put on a big end bearing under load and don't get me wrong top end oils are good not nocking them at all just not needed in my saws cranking out a whooping 6hp (cough) or some *s-word lol...
Used to be called Active 2T (red oil) now called Garden 2T (now blue oil) blue is even better yeah? tru dat I read it on the internets ha..

 

[rogue60]

Na will be this one

http://www.supercheapauto.com.au/on...cle-Oil-1-Litre.aspx?pid=1105#Recommendations

Yep that's it.

 

[Brewz]

looks like you can still get both mate

https://www.autobarn.com.au/castrol-mower-oil-2t-self-mix-2-stroke-1l-4100116

https://www.autobarn.com.au/castrol-activ-2t-2-stroke-1l-motorcycle-oil-cast-4100595