026/MS260 Build

[Mastermind]

OK fellers........here's how we do a 026.

I had these one the bench a few days ago.....

 

[Mastermind]

I start by flattening the piston. That means knocking off .045"

First, gotta get it right in the four jaw.

I like to push it tight against the chuck with a flattened live center.



Then get the run out down to just a few .001s

 

[Mastermind]

Then......just start hacking at it. lol

 

[Mastermind]

Thanks for the candy Cobby.

 

[Mastermind]

If y'all ain't ever used one of these Stihl circlip installation tools........call Dave and buy one. Best thing since sliced bread.

 

[Mastermind]

 

[Mastermind]

After cutting .060" from the squish band, I'm now cutting the plating at the bottom of the jug to keep from chipping when I cut the bases.

 

[Mastermind]

In these pics, you can see that not all 026/260 combustion chambers are the same.

In the first two pics, the MS260 is on the right.....



MS260


026

 

[Mastermind]

The rest is just basic port work.......so let me show you Jon's work on the mufflers.

The front covers on these saws blows the exhaust on the PTO side of the case, and makes a mess.......so.....



Then some port matching.

 

[Mastermind]

Making the PTO side deflector.

 

[Mastermind]

And done......

 

[czar800]

Have you ever milled off the base in the past?

 

[junkman]

I like these lil saws .

 

[Mastermind]

Have you ever milled off the base in the past?

No sir. I turn the base on the lathe.

I would like to be able to mill the case on a few saws........but this one turns out ok like this.

 

[junkman]

Where does compression end up ?

 

[Mastermind]

Where does compression end up ?

225 - 240

 

[Tor R]

View attachment 5465

pop up

 

[Mastermind]

pop up

 

[Tor R]

I can see you still have it in your mind
Great thread Randy!

 

[Mastermind]

I still remember how.

And on some saws it makes a lot of sense.