The mighty stihl 064 and early 066

[066 redeye]

Also should mine have the plastic tag.
Had no tag on it so fitted a metal one.
Chris.

 

[jacob j.]

Whats the paper towel for?

064s aren't house trained as a rule...

Is that the original jug?
Thought the ally wheel saws had no decomp.
But as usual prob wrong.Maybe the later ally ones did.
None of my ally 066s have decomp.
@jacob j.

I can't remember...I'm getting too old. I know when the poly flywheel saws came out as a flat top, they all had
compression releases. Those cylinders and the cylinders just before those are very desirable. I just put one of
those cylinders on a later metal flywheel saw and it is a strong runner, stronger than the 661 I built last
year. Although I would bet that if both were ported, the 661 would be stronger.

 

[markds2]

Is that the original jug?
Thought the ally wheel saws had no decomp.
But as usual prob wrong.Maybe the later ally ones did.
None of my ally 066s have decomp.
@jacob j.

The last of the alloy flywheel small crank saws definitely had a decomp. I recently rebuilt this one, which I worked out was from around 1995, it had a dual key flywheel and unlimited coil (which I actually used on my Treemonkey RL 066 build https://opeforum.com/threads/treemonkey-red-light-066-build.22196/) and a Mahle decomp cylinder. Was a strong runner although the exhaust was sitting at 95 or 96.

 

[huskyboy]

The last of the alloy flywheel small crank saws definitely had a decomp. I recently rebuilt this one, which I worked out was from around 1995, it had a dual key flywheel and unlimited coil (which I actually used on my Treemonkey RL 066 build https://opeforum.com/threads/treemonkey-red-light-066-build.22196/) and a Mahle decomp cylinder. Was a strong runner although the exhaust was sitting at 95 or 96.
View attachment 285651

Yup your right. I actually did the research and traced my serial number to be just before they came out with the poly crank saws. Poly serial # changeover was 133917. Decompression serial # changeover was 132231. My serial # was 133639983. I also had a mahle decomp cylinder.

 

[huskyboy]

I have a ks non decomp 066 cylinder I was excited to have timed but was disappointed to find these numbers. Especially after hearing all the hype about the early cylinders. I guess there not terrible but was expecting better. I also have a 064 KS cylinder here that I have not had timed yet. My 064 has a mahle cylinder and it’s a good runner.

 

[MustangMike]

I'll bet those #s will work better than you think Mason ... lots of 066/660s run strong with and Ex of 96-98. Ex of 100 or more seems to limit RPMs in many saws. May have something to do with the stroke being longer than on a 440 or 460.

 

[redlight066]

Saved this one from the scrap heap. It belongs to one of my customers. Still starving for fuel a little. The original WJ35 was ruined by the previous builder. I have another WJ35 but I'm not parting with it. It's got a WJ69 now, I may drill the main jet just a hair. Or just leave it at 1.5+ out on the high side.

I need to make a correction. It does have the correct Prufex coil (CDIC) Cheers, Rich

 

[Wood Doctor]

I installed an MS660 top end on a vintage 064 after the owner straight gassed it. I had an old 660 top shroud with a hole for the decomp valve. To my surprise, it bolted right on. Yes, it looks a little goofy but he could care less. He loves the decomp valve. It's saving his arm, wrist, fingers, and shoulder.

 

[Basher]

I have a ks non decomp 066 cylinder I was excited to have timed but was disappointed to find these numbers. Especially after hearing all the hype about the early cylinders. I guess there not terrible but was expecting better. View attachment 285659View attachment 285660 I also have a 064 KS cylinder here that I have not had timed yet. My 064 has a mahle cylinder and it’s a good runner.

Was that with the gasket still in place, asking for a ,friend?

 

[huskyboy]

Was that with the gasket still in place, asking for a ,friend?

Can’t remember. Numbers wouldn’t have improved much either way though.

 

[Basher]

Can’t remember. Numbers wouldn’t have improved much either way though.

They are not bad as is, just wondering what the squish was with a gasket, enough room to drop the cylinder 2 -3 degrees.

 

[redlight066]

Was that with the gasket still in place, asking for a ,friend?

Yup. Oem gasket.

 

[BonScott46]

I have a 1996 flat top 066 with alloy flywheel and thick based mahle with a decomp. SN#133641907. Port shapes are very round, more round than any other cylinder i have seen. Only thing i have done is enlarge the stock outlet and cut off the end of the baffle. Runs ok but my KS 064 blows the doors off it.

 

[huskihl]

Some of the non-decomps had good numbers and some of the early decomps had good numbers. And some are just meh. The ones with higher smaller transfers up around 120 are the ones that seem to run the best.

 

[markds2]

Saved this one from the scrap heap. It belongs to one of my customers. Still starving for fuel a little. The original WJ35 was ruined by the previous builder. I have another WJ35 but I'm not parting with it. It's got a WJ69 now, I may drill the main jet just a hair. Or just leave it at 1.5+ out on the high side.

I need to make a correction. It does have the correct Prufex coil (CDIC) Cheers, Rich

Hey Rich, thanks for sharing, sounds nice and cuts fast! I do notice that it exhibits the same 'pop' or miss mid cut that my TM066 did with the same CDIC RL limited coil installed. This miss only went away when I found and installed an unlimited coil and flywheel combo of a slightly later 066. From what research I did it is a sign that the coil is on its way out..

 

[ManiacalMark]

Is that the original jug?
Thought the ally wheel saws had no decomp.
But as usual prob wrong.Maybe the later ally ones did.
None of my ally 066s have decomp.
@jacob j.

Metal Flywheel saws had a decomp in 95. Poly flywheel saws had a decomp with a lighter shade of orange flat top cover and a plastic tag. The short case poly saws were flat top and only made the first 2 years or less than that (96-97).

 

[Wood Doctor]

Carb observation here. The original carb on an 064 AV simply would no longer start or continue to run the saw. I had an almost-new MS 660 carb (WJ-69) in my boneyard so I installed it instead. The saw started right up and runs beautifully. The end cover, of course is different, so I inserted a small piece of foam rubber in the port to help keep out dust and dirt. Anybody else tried this fix? WDYT?

 

[qurotro]

Carb observation here. The original carb on an 064 AV simply would no longer start or continue to run the saw. I had an almost-new MS 660 carb (WJ-69) in my boneyard so I installed it instead. The saw started right up and runs beautifully. The end cover, of course is different, so I inserted a small piece of foam rubber in the port to help keep out dust and dirt. Anybody else tried this fix? WDYT?

You mean the measuring diaphragm side's vent? My 064AV comes with WJ6 with no vent. that cap can be swapped.

 

[Wood Doctor]

It looks like this (11):

Stihl calls it an end cover. What you are saying is that I can swap that out with the end cover that was on the 064 carb. I thought about doing that, but it seems that all that port does on the 660 is feed into the air filter, which protects it from dirt, dust, etc. I had to make a small adjustment to the low-speed setscrew, well inside the range of the limiter. It was a pleasant surprise to hear that engine purr again.

 

[trooney]

I've also got a Bing I'm putting on my 064 build. Those compensating carbs are for people to rely on instead of fixing a possible problem in the long run. I think the Tillotson is a good carb too. If you got a spare cover laying around, I'd go that route.