Return of the Stihl 066 Magnums

[HolmenTree]

With my tree service season now in full operation I had to make my main chainsaw decisions.
With the recent humid warm weather the hot starting frustration with the 8 year old Husqvarna 562XP is now officially retired.
My buddy is teasing me with his new MS462 CM but I'm looking at my freshly OEM rebuilt1992 and 1997 066 Magnums sitting up on the shelf.

Originally intending to sell the 066 pair after a complete rebuild with included  all new rubber parts and intake manifolds. I couldn't sell them to break even for the OEM parts I put in them.
I got 28 years  out of my oldest 066Magnum -20" could probably now get another 28. This 2nd year red light I made into a hybrid with some 1980's 064 parts to lighten it up to the weight of a MS460.

The 1997-28" 066Magnum is a great workhouse. This was the last 066 model before all the EPA detuning changes came to be. I got a couple newer 36" bars for it if needed.
I'm very fortunate to own this two saws. Great to put them back in service, just like working again with an old friend.
No matter how hot with humidity or how cold these saws have  never let me down.

If I was logging 8 hours a day 5 days a week yes the MS462 would be in my hands. But with my stop and go tree service work these 066 fit the bill perfectly.


 

 

[realzed]

Looks like they were pictured from somewhere near the shores of the famous Burntwood River..   ;D

[lxskllr]

Best part is you already had them, and have a backup if one dies. Beats spending a bunch of money.

[Al_Smith]

It stands to reason with a full rebuild you'll get another 28 years out of them .

[HolmenTree]

Looks like they were pictured from somewhere near the shores of the famous Burntwood River..   ;D

Randy , yep right off my front yard.
Only me and my neighbor have riverside view in all of town.

[HolmenTree]

It stands to reason with a full rebuild you'll get another 28 years out of them .

Al, unfortunately it may out live me .
I'll be 90 in 28 years :D

[HolmenTree]

Best part is you already had them, and have a backup if one dies. Beats spending a bunch of money.

Yes I got lots of spare parts too. 
Surprisingly my Stihl dealer  can still get lots of NOS parts for them.

[Mad Professor]

I'll add reliable and VERY simple to work on.

Bet you are glad you hung on to them

[HolmenTree]

I'll add reliable and VERY simple to work on.

Bet you are glad you hung on to them

I sure am happy MP,
12 years ago I bought a brand new 2008 395XP to replace my '92 066 mag.
About all the 395-32" was good for was an expensive stump lowering saw for the stump grinder.
That big bulky saw with the front chain tensioner was smooth but had no more power then my early 066.
Ended up selling the Husqvarna a few years ago.
The 1997 066 was given to me years ago . It was bought by the local lumber company to cut up lifts of reject lumber into stickers for the shipping department.  So happened the fork lift operator straight gassed it and it sat in their shop for a few years. The saw only had a few months on it.
That saw is much better built then the '92 066.

[HolmenTree]

 

 

 

 

[Air Lad]

They are keepers 

[421Altered]

Which one is the 97?
And what do you mean that the 97 is much better built than the 92?  Not picking a fight, just want to know as I've got a 066 magnum that has the decomp valve, given to me and I'm thinking about rebuilding it.  I'm trying to find out all I can about the 066 magnums.  Thanks.

[hedgerow]

Good to see a couple good old work horses back in the line up. 

[HolmenTree]

Which one is the 97?
And what do you mean that the 97 is much better built than the 92?  Not picking a fight, just want to know as I've got a 066 magnum that has the decomp valve, given to me and I'm thinking about rebuilding it.  I'm trying to find out all I can about the 066 magnums.  Thanks.

The 1997 066 model is the one with the  longer bar.
The second year 1992 066 is basically a 85cc 064 with a big bore 92cc P/C on it with a bigger flywheel fan and wider rewind housing. This early  066 has  the same crankshaft the 064 had in the 1980's. When a 92cc  big bore piston is put on a crankshaft designed for the balance factor of a small bore 85cc piston more vibration is the result.
The 064 was first introduced in 1986.
Don't get me wrong the early 066's were real fast ripping hotrods, they had good port timing #'s but over the next 6 years of upgrades the 1997 066 was about the best they came to be. 
1998 was the first year of the round top 066 which carried into 2002 with the MS660. What was lost in 1998 was the EPA rule  changes to make the cylinder burn cleaner. What that did was detune the port timing decreasing power. From that year on the barn burning horse power days sold right off the dealers shelf were gone. And yes also the dual outlet port muffler in the USA.

[421Altered]

Thank you very much HolmanTree for that great info!  How do I tell by the serial number what year my saw is?

[Old saw fixer]

We sold and serviced many an 066 back in the day, before the mechanical cutters replaced men and saws.  Most of them went out with 20" bars.  I worked weeknights, the loggers liked that they got overnight service.  I'd be up to my elbows in saws and another logger would bring a bunch in and really hoped I could get him 6 ready to pickup in the AM. 

[421Altered]

my 066 magnum has the single port muffler, and the HD air filter, but does not have the see thru fuel tank.  The "Magnum" decal is in front of the decomp valve.  And the 066 label looks like plastic imbedded into the flat top cover.  It is not metal with rivets.  Do those things tell anyone about what year mine may be?

[Al_Smith]

They get beat up over time and the new replacement parts might not always be exactly like the originals even if they are new OEM parts .My bud Tom,a tree trimmer had the fastest stock 066 I ever saw .I've operated modified versions and is was close .It was stolen and the replacement 660 was not nearly as robust .I offered to modify it but he declined .That said the 066 is a very desirable saw .I really don't actually need one but it's on my list in case one comes up,rebuilder of course,frugal you know  ;)

[HolmenTree]

my 066 magnum has the single port muffler, and the HD air filter, but does not have the see thru fuel tank.  The "Magnum" decal is in front of the decomp valve.  And the 066 label looks like plastic imbedded into the flat top cover.  It is not metal with rivets.  Do those things tell anyone about what year mine may be?

421, I'll need to dig out my old 066 notes later today. I can give you serial # etc. Somewhere on this forum I probably have them posted.
Sounds like you have a 1996 or '97.
The decomp and plastic top cover badge came out around then.
My 1992 066 has a translucent fuel tank. Sounds like you got a solid 064 tank on your saw.
The Magnum dual outlet muffler was discontinued in the US around 1995 due to OSHA restrictions.

[HolmenTree]

Ok I got some Stihl  066 #'s.

Big thankyou to Definitive Dave for collecting the information.

▪︎Early 1994 cylinder base got thicker going from M6x20 screws to M6x25.
▪︎Mid 1994 beefed up PTO crankshaft bearing with 13 roller bearings from 12.New rubber coated cylinder base gasket after serial#129 588 002.
▪︎Early 1995 in the USA OHSA forced the discontinuation of the dual outlet Magnum muffler after serial# 131 960 509  dropped from 7.8 to 7.2 hp
▪︎Early 1996 new poly flywheel and increased crankshaft taper and larger bearing from 13.5mm to 15.4mm after serial#133 917 066.
▪︎Mid 1996 decompression valve installed on all 066 from serial #133 980 509.
▪︎1997 first plastic name badge on top cover after serial #134 459 523
▪︎Early 1998 Shrouds and filter changed from square to rounded.
Limiter caps on carb, detuned porting and EPA labeling after serial#139 176 186?
▪︎Late 2002 model changed to MS660.
▪︎066 March15 1991 to September 15 2002.
MS660 October 15 2002 to ?? 2014.
My 1986 064 is serial# 116 468 370
My 1992 066 is serial# 126 316 881
My 1997 066 is serial#  134 989 911

[gspren]

  I shouldn't follow threads like this because now I want a 066 even though my 044 is all the bigger I ever need. It would be best if I don't see one at a yard sale. :D

[421Altered]

HolmenTree,  I can't thank you enough for that great info on 066 serial numbers and features!  Mine is serial number 134988720, so it is a 1997 model!!  Yay!!  Also, it's almost a brother to your's, only 1191 saws younger than yours!  I was wondering if it would be worth rebuilding, so, with the info you and other's have provided, I'm all fired up!  I've got to finish an 084 I'm rebuilding now, then I'll get on it.  Only thing about the 066 that worries me is the ignitions.  I have not torn it down, so I have no idea what it has inside of it.  The saw was given to me in non running, but complete condition.  Good thing is it's not locked up, however, it has practically no compression, just goes right down the starter rope!!  Thanks again!!

[HolmenTree]

You're welcome 421, lots of OEM parts out there. See your Stihl dealer he can still get NOS parts for the old 066's. 
I replaced both saws aging rubber intake manifolds with NOS my dealer ordered in. Those manifolds will save you alot of money down the road when you rebuild your saw.
That little orange rubber tank vent that looks like an umbrella you must change out too. Many guys don't  think of them and wonder why their saws are leaning out .
Change the pulse hose too .

[Tom King]

I just ordered a service manual off ebay yesterday.  I've been in mine several times, but never got around to getting a service manual, and one popped up yesterday, just by chance.

Thanks for the tip on the tank vent.  I hadn't thought to change that.

[421Altered]

HolmenTree,  Thanks again very much for the great info.  Also the tip of the umbrella vent, I hadn't thought about that leaning it out.