STIHL The Official Stihl Chainsaws Thread

[Al Smith]

If I recall a lot of builders tried and didn’t like pop ups for various reason. If I recall when I asked tree monkeys opinion I was told they are a waste of time because they mess with the fuel burn across the piston top so the extra compression was useless almost.

Once again it's an opinion therefore an option .I have done several all with good results .I didn't get the idea from any info on any chainsaw forum .Rather from years of working around several companies building automotive engines and 29 years working for Ford Motor company .Plus the days of my youth around stock car engine mods .
The idea of a pop up is not to raise the compression but rather change not only the flow over the crown but how the flame front propagates .Having said that I've seen plenty using a flat top that ran just dandy so it's a choice .

 

[RI Chevy]

MS 261 CM #2 , don't have pictures of the first one I bought . Bought the first one new , this one had been used twice according to the guy I bought it from . Looking at the muffler I don't doubt that a bit .

Looks like a Version 1

 

[Eddie Southgate]

Looks like a Version 1

By #2 I only meant that it was the second one I have bought , both were made after the middle of 2019 . I got this one off of ebay very slightly used , the first one I bought new . Liked it so much I needed another one so I would have one stocker and one to mod .

 

[RI Chevy]

Hmmm. Interesting. The clutch cover looks like a Version 1. TY

 

[DND 9000]

Looks like a Version 1

He says it was made after the middle of 2019: So it can only be the revised version of the MS 261/261 C-M. That change was near the end of 2015. Also his serial number is way above the changed version in 2015. The change on the MS 261 C-M version was from serial 507... on, and his saw is 5185229... can`t read it completely.

Hmmm. Interesting. The clutch cover looks like a Version 1. TY

That saw has the wrong sprocket cover on it.

 

[Eddie Southgate]

Enlighten me , what is the difference in the covers . I'm in another state so I don't have access to either saw right at the moment or I would compare the covers on the two for myself . I am not a collector ,just a small time accumulator . That saw came from California and I believe the tag said made the seventh month of 2019 for a date of manufacture. The new saw came from way up north somewhere and I think , but am not sure , was dated somewhat later in the year.

 

[DND 9000]

I don`t know the exact difference, but according to Stihl the new cover has to be used for the new version. I think it has something to do with the tightness and the different design of the compontents when they are mounted. Also the new cover has bar nuts which are adapted to the new cover.

 

[rocketnorton]

captive nuts?

 

[RI Chevy]

Both V1 and V2 have captive nuts. V2 clutch cover has much more sculptered look. V1 is plain like the photo shows.

 

[RI Chevy]

He says it was made after the middle of 2019: So it can only be the revised version of the MS 261/261 C-M. That change was near the end of 2015. Also his serial number is way above the changed version in 2015. The change on the MS 261 C-M version was from serial 507... on, and his saw is 5185229... can`t read it completely.



That saw has the wrong sprocket cover on it.

Yes sir. The clutch cover is like throwing a knuckle ball to me. Lol
I could tell cover was V1 cover.

 

[PogoInTheWoods]

Both have 8mm captive nuts but have different part numbers for em as do the studs. There are three different PTO side case halves as well. Maybe some differences in the mating surfaces at the bar mounts?

 

[Eddie Southgate]

Here are two pictures of the first one I bought . These are auction pictures not mine . There is a lot of difference . I never even noticed ! Reckon how this happened ?

 

[RI Chevy]

That clutch cover is a version 2. See the difference?

 

[Eddie Southgate]

Yup !

 

[Maintenance Chief]

Once again it's an opinion therefore an option .I have done several all with good results .I didn't get the idea from any info on any chainsaw forum .Rather from years of working around several companies building automotive engines and 29 years working for Ford Motor company .Plus the days of my youth around stock car engine mods .
The idea of a pop up is not to raise the compression but rather change not only the flow over the crown but how the flame front propagates .Having said that I've seen plenty using a flat top that ran just dandy so it's a choice .

I've noticed slightly domes pistons on several saws I have XL-12 and a Remington, so pop ups can't be that far off.

 

[Al Smith]

A hemi domed is a very old design that still works .I've got a set from a 1950 Indian motorcycle that are hemi domed In the last several years cutting down the combustion chambers has became more popular

 

[Al Smith]

FWIW A Stihl 038 AV has a hemi domed piston and also a set back combustion chamber .Just general info .

 

[Maintenance Chief]

Piston of the ms441 cleaned up ok.

 

[Maintenance Chief]

Cylinder cleaned up well too but, the fist ywo pictures show the enlarged spark plug hole that the insert came out of , threads look beet than they are.

 

[Maintenance Chief]

As you can see the muffler mount treaded holes have some issues also . I like that the heli- coil is growing out of the side of the wall and that there was a failed attempt to drill/ remove the old broken shank of the first screw but evidently they just gave up.
Im not sure whats fixable or reasonable to fix on this cylinder, I know i could get the steel bit of screw and heli coil out but I dont have a tig welder . What's it usually run to have it welded up?