mufflermod 066, ps9000, 2171

[KahNon]

Hi all,

i am new here and could use your advise. From oct till april i cut firewood almost every morning until 1 pm
before going to work in the afternoon. I mostly cut oak, cherry and some birch. I own 4 chainsaws. Stihl 026
and jonsered 2171 which i bought used from a treeworker and have used for 3 years now without any
major problems. Last week i bought a dolmar ps9000 and a stihl 066 with hardly any hours on them. I
adjusted the carbs and both saws are running great. Now i was reading up on  muffler modding and was curious
if that would be interesting for the stihl 066 maybe.
As i understand i need to install dual port casing muffler (1122 140 0603), then remove limiter caps with
Limiter cap puller (5910 890 4500), then after setting the carb put new caps in (4203 121 2700). Are there
any other modifications i can do like new airfilter f.e ? I don't think saws get woods ported over here because
i haven't seen any yet. And for me that would be overkill as it is not my livelyhood. Nothing beats working in
the woods. BTW i have alot of 30" + oak this year. What do you guys think, would the muffler mod be good
for me ?

regards

[Al_Smith]

Of course some muffler work will improve how it runs .Keep in mind though you have to readjust the carb because it will need more fuel .

Generally speaking an 066 runs just fine without doing a thing to it .Now just how often do you really need it cutting firewood any way .

Excentric gear heads like myself and others get a kick out of cranking power out of them but keep in mind it's not for everybody .

[KahNon]

Thx for your input. If i do the mod, does the muffler need any further adjustment or just put it on ,readjust the carb and put new
limiter caps on ? Does anybody know if the dolmar ps9000 or the jonsered 2171 have similar dual port mufflers available or do
i need to open them up myself ? This is all kinda new to me. I cut approx 30 cords a year. I added some photo's of the new
additions.

[Al_Smith]

 I can't tell you off hand how big of a hole to put in the muffler .I myself go with about 80 or so percent of the exhaust area .Then too my mufflers are only the shell, no baffles or screen just the can .

You go too big you might get one to just scream  but chances are it could be running lean too so keep that in mind . If you can get the carb tuned so you get that "4 cycle " cackle you should be okay .Run it a tad,let it cool then check the plug .White is too lean black is too rich .Light tannish color is just right .Better rich than lean .

[MMFaller39]

I'll trade you my woods ported 064 for it.

[KahNon]

Have been reading up on this saw, i think it is the red eye without decompression valve from around 1991. Is it possible this saw has no limiter caps then?   So adding the dual port muffler won't be an option i guess because the red eye has limited rev coil. Tuning it in the wood will be best option i guess. Been looking at the parts list for this saw. Is it worth replacing the standard air filter with the high duty air filter ? The full wrap handlebar also seems a good thing to add. Are there any other parts that need replacing when installing the full wrap ?

Tom

[Cut4fun]

Looking at your 066 carb there is no limiter caps.    There is the rev-limiter  though.

Carb tuning link http://www.madsens1.com/saw%20carb%20tune.htm


This is all 2nd hand info from reading. The redlight saws were rev limited to 12.5k and the little led red light would come on.

This first part is more info on Willards 066 RL.

(((066 Mag Artic red light, with dp muffler serial # is 126316881. This "ARTIC" has the thermostatically controlled heated carb and no heated handles. I didn't bother getting the bulky wrap handle. The heated carb still heats perfectly today.
I bought this saw brand new in the summer of 1992 so I presume its a 1991 model. I did upgrade it about 6mths after I bought it with the newer flywheel and module.
18 years later and a few thousand hrs on it, it still has lots of compression, I never had the cylinder off of it. Only 2nd to my 090AV, my 066 is the toughest saw I ever owned, never broke a crank, bearing, etc.
Willard.)))))

Again all 2nd hand info. So take it for what it is worth. This is just stuff I have heard since I dug up info after getting mine. Even though mine was updated I wanted to know too .



((((The red light 066 was only made for a short period of time. They were only made on a very early flat top 066; there was no later model 066 using them. There was an RPM rev limiter in the coil and an LED lead running from the coil to an LED light at the side of the saw. The light lit up when the rev limit was reached and the coil was cutting out. This was so that you could tune the carb H screw to lean it out just until it was cutting out, and the LED light was flashing. For that reason these saws had engines that were fairly bullet-proof; it was nearly impossible to score the engine with the limiter in them. Only straight gassing did them in. Or the bearings went out, as was the case with mine. The swapped out red light and later models of 066 with the AL flywheel and unlimited coil had a common problem with spinning the flywheel side of the crankshaft off because of over revving. So Stihl made the flywheel side of the crank thicker in 1996 and replaced the aluminum with a poly flywheel. They also changed the ignition modules to to advance the timing at high revs on the later poly coils. The AL flywheel coils are straight-line timed ignitions; they do not have an advance curve in them like the poly modules do. The CDIC coils also had a timing retard in them at low speed for easier starting.

In the above post, the 1303 module was in the 064, and not the 066. The red light 066 coil module was a Prufrex CDIC, Stihl PN: 1122 400 1307 (similar to the 064 module, but it has the LED lead). It was changed to an Iida unlimited coil module, Stihl PN: 0000 400 1300, in 1993 and retained the AL flywheel. That was changed to an Iida unlimited coil module, Stihl PN: 1122 400 1311, in 1994. The 0000 400 1300 coil is a generic coil and is still used in some of the new larger Stihl saws. The 064 also had a CDIC coil put in them from 1989, but there was no red light limiter LED. Note that only the 064 AL flywheels have two key slots. This is to accomodate different types of ignition; one was for electronic ignition, and the other was for analog points and condenser ignitions. On these flywheels, B stands for Bosche (old points) and P stands for Prufrex (new electronic).

Quick histry of the 066:

Early models from early '91 to late '92 had the 'red light' LED and limiter coil with AL flywheel.

Loggers figured out the limiter and swapped in the non-limiter coil. Stihl figured out what was being done and came out with the non-limted coil model.
Original red light saws with limiters were bullet proof and immune from air leaks and lean scoring as well as flywheel sheer (both good).
Problem with the limiter coils fading in time and rev limits lowering to near 10k from the original 12.5k (bad).

Later-early model 066 from late '92 to early '96 had the non-limiter coil with the AL flywheel. The LED was removed (a weird gimmik at best).

Problem with this saw was that if they were revved high and sunk into a wood cut and bogged down, the inertia of the AL flywheel sheared off
the crankshaft, and self-destructed the flywheel, saw case, crank, or all of them (not good).

Late model 066 from '96 and on were updated with a beefier crank and a polymer flywheel which is a lot lighter, and not prone to sheer from built up inertia. The poly flywheel also had a different ignition coil that had an advanced ignition curve at the top end. The decomp button was added at some point, with the humped top.

The late model 066 was made obsolete with the MS660, but they remained essentially the same saw.

The 066 came in several models. The MR (Mag Rescue) model had a 3/4 wrap, a PNW sprocket side cover and large falling dogs. The early M (magnum) model had a dual port muffler. The Arctic model had a wrap handle heater and a mini alternator in the flywheel (both AL and poly flywheels have a heated handle/carb version). There are also Aussie AUS and Canadian CDN versions of the saws. The Canadian model had a full wrap option. The Australian model came with a high output oil pump. They had light, medium and heavy duty air filter options. They came with an Elasto-start as an option. They also had a variety of carbs, some had a fixed H jet, some with heaters to keep the carbs from icing up.))))))

More info. From a stihl guy out in the PNW

Early 1994 - Thin cylinder base ( Red light etc) changed to "thick base". Base screws changed from M6x20 to M6x25


Mid 1994 - Beefed up crank - Crankshaft BIG end changed from 12 to 13 roller pins from serial number 129 588 002. At the same time, the cylinder base gasket changed to rubber coated Steel (so quit using the junk aftermarket gaskets!).


Early 1995 - OHSA (NOT EPA) forced the dicontinuation of the Dual port Magnum muffler from serial number 131 960 509. HP dropped to 7.2


Mid 1996 - decomp valve fitted on all 066 from serial number 131 960 509


Early 1996 - Poly flywheel installed and crankshaft bearing increased in size from 13.5 to 15mm from serial number 131 917 066

Early 1998 - shrouds and filter box changed from squared to "rounded " type. Limiter caps on carbs and EPA labling...


Early 2002 - Name changed from 066 to MS660.


Lot's of ignition changes and carbs over the years...

[Rocky_J]

A bunch of good info there, Kevin.  8)

[KahNon]

thx alot for all the info, i also see that Windthrown wrote alot about this. So it is probably not possible to fit the stihl
DP muffler without putting an unlimited coil in ? I guess i will leave it as is for now. The saw is harly used and looks like new. Still has more HP then a stock 660.
Any ideas on modding the dolmar ps9000 and jonsered 2171 ?