661 R&D

[Time's Standing Stihl]

Hmmm....that saw looks familiar.

If it runs like an ape...it's staying on there!

 

[jmssaws]

Hmmm....that saw looks familiar.

If it runs like an ape...it's staying on there!

Your saw is for demonstrated purposes only. I can scrap up one or use my minty 660 but I hate to.
I can put one together to try it on.

 

[mdavlee]

Depends on which oil and how its tuned if there's wash in a couple cuts or couple tanks.

 

[jmssaws]

Mtronic and the oil i use surprised me that there was one already.

 

[jmssaws]

Suggestions on cylinder #1?
Anybody got something they want to try?

 

[Time's Standing Stihl]

Have you checked the case capacity compared to a 64/66? Kinda curious

 

[jmssaws]

Have you checked the case capacity compared to a 64/66? Kinda curious

No but I will in a minute.

 

[jmssaws]

I got my 066 out and fixed the muffler but I didn't have a dp cover handy so it has a stock lid and a single outlet. Still runs mighty strong, ran it and the 661
The 066 feels twice as fast but it's not
066 11.4 11.7
661 11.4 11.4

 

[Time's Standing Stihl]

 

[Moparmyway]

Suggestions on cylinder #1?
Anybody got something they want to try?

I'll suggest:
98-99
124-125 (start opening)
79

 

[jmssaws]

I'll suggest:
98-99
124-125 (start opening)
79

That's what I have in the other cylinder
But the intake is 82

This cylinder is 101 121-125 77
And has 25lb more compression

 

[Moparmyway]

That's what I have in the other cylinder
But the intake is 82

This cylinder is 101 121-125 77
And has 25lb more compression

Exactely !!!

 

[jmssaws]

Exactely !!!

Yeh but they run the same.
The 101 cylinder might be a little bit stronger,the 99 cylinder just sounds faster.

 

[mdavlee]

Seems like the 661 cylinders run about the same with different numbers. I don't know what to try next besides higher exhaust to get longer blowdown more like a 7900. Case capacity is different some but will be real hard to measure with the doohickey

 

[jmssaws]

Seems like the 661 cylinders run about the same with different numbers. I don't know what to try next besides higher exhaust to get longer blowdown more like a 7900. Case capacity is different some but will be real hard to measure with the doohickey

The higher exhaust cylinder has a cackle to it and it makes it sound faster but there pretty much the same, if anything it's a touch slower maybe. They both run damn good.

It does make you wonder.
One is 99 121 82 180lbs
the other 101 123 I think 77 195lbs
And they run identical.

 

[mdavlee]

I wonder how 95 125 75 would run? Be a lot of intake filling.

 

[jmssaws]

I think if the transfers are working good then the exhaust and intake can be all over and run the same and that's why these saws are like they are.

The transfers are very efficient.

 

[leadfarmer]

Well Jas it be 2days an no postin, sombody steal all your saws....

 

[Redfin]

That may mean he be beatin the revs out your saw paco.

 

[jmssaws]

I ran it a good bit today.
Gonna go back to cylinder #2 and run it a bit,I think it's stronger than #1 but anymore they all feel the same.
I have to video everything and time them.