Stihl 024AV VS 024AVS

[aarongd]

Morning Stihl Gurus. I am wondering what the difference is between the Stihl 024 AV VS 024AVS? I am building a few and wasn't sure of the difference. Additionally, i have several 024 Stihl's that have 2 bar studs/nuts whereas i have some with only 1 actual bar stud and one somwhat of a stud with a common screwdriver slot in it. Any idea of the purpose of the fake screwdriver slotted stud? They are both on the 024AV and the 024 AVS? Thx Pics coming

 

[aarongd]

Pics

 

[Wood Doctor]

Taken from service manual, this should help. The super has more power and the same stroke as an 026.

 

[Mad Professor]

pistons cylinders and crank are different on 024 vs 024S. Same size bores but super is longer stroke

 

[aarongd]

So s in this case means super. Great to know. Have 2 ea Avs’s left. How about bar stud?

 

[Bob Hedgecutter]

You can turn an 024S into an 026- but you cannot do the same with an 024.
The extra 2mm of stroke sorts that out.

The dummy bar stud is there on single stud saws to keep the bar in line. So the bar does not have a point of axis of only one stud it can move around, thus altering chain tension.
Small single stud saws like the 200T and 201T have the same, the short screw protrudes enough to align the bar slot, but does not come through the side cover nor need a nut, there is enough holding power with one stud for the smaller bars these saws most commonly use.

 

[stihltech]

You may also find a different lower rod bearing on an 024. Make sure you use one with a caged rod bearing.

 

[aarongd]

Awesome. Thx for the info. I knew someone here would know. Thx again

 

[BrettS]

I have also noticed there is two different cylinders, one is open port and one is closed port, both are the same bore size (at least on the 024 cylinders I have).

 

[aarongd]

built 2 of them other day. Not 024AVS but 024 AV, Extremely impressive for small saw. Wi;; cut circles around Stihl MS290/291. Quite amazing closed port vs open port, Would rather run these than ms290/291 all day long!!!! And way lighter!!!

 

[9050LX]

I'll not sell mine.Just feels like a good handling predictable tool.

 

[Paul Fithian]

You can turn an 024S into an 026- but you cannot do the same with an 024

Yes you can. I recently upgraded my 1985 024 AVS with a 44.7mm Mahle P/C.

I am in the process of upgrading a 1986 024 AV with a 44mm Mahle cylinder and Meteor piston. Here’s what timing numbers looked like before shaving 0.016” from the base

 

[Bob Hedgecutter]

Yes you can. I recently upgraded my 1985 024 AVS with a 44.7mm Mahle P/C.

Thats what I said- you can with an AVS because the S is for SUPER and that one shares the stroke of the 026 which is 2mm longer than the standard 024AV,

 

[Paul Fithian]

There are many examples of a 44mm P/C on an 024 AVS. There are only a few examples of a 44.7mm P/C on an 024 AVS, one is mine that was recently done and documented in another forum. Runs perfect and way more powerful than a stock 024 AVS. See this video for comparison to a stock MS 251:

Without a base gasket, squish for a 44.7mm cylinder on an 024 AVS is 0.019"

Conventional wisdom is that a 44mm 026 P/C won’t work on an 024 AV. But there is more to the story beyond the 2mm stroke difference. Deck height, con rod length, and piston height are other factors in play here.

Have a look at the timing numbers I posted above. A 44mm P/C can be used and work great by adjusting the transfer port height to 120. Should rev higher than an 026 due to the shorter stroke.

I had 0.016" removed from the base of a Mahle 44mm cylinder to get 0.020" squish without base gasket. Next step is to install it and document timing numbers to determine how much to remove from the upper side of the transfer ports to get them to 120 degrees.

 

[Paul Fithian]

I can report the 024 AV build with a 44mm Mahle runs perfect. Ported timing numbers ended up at 0.022” squish/103/125/76



Both of these saws were West German built. Now more powerful than when Stihl made them almost 40 years ago.

 

[Paul Fithian]

Here’s a video of the 024 AV with the ported Mahle 44mm 026 cylinder, 20” bar in red oak