400 CM Build

[drf256]

Seems like we need a build thread here. It’s been too long and traffic has slowed, I hope it gets busier.

I’d doing a good friends 400. The saw was NIB when I got it. As time is tight with everyone, I’ll post along as I go in no particular order.

This is only the 2nd 400 I’ve done. To clear any confusion, this is the 50mm older version of the 400cm. It has a factory magnesium piston which I had been told would allow the piston to score with no deposits or damage to the jug. Many have since have called BS on that after working on scored ones. If anyone has a picture, please feel free to share.

Disassembly time. Got the jug off and on the lathe fo a band cut. The jug is beautiful from the factory and a far cry from the “0” series cylinders.

 

[drf256]

This won’t be a speed build by any means, so I hope you’re all patient.

 

[Duane(Pa)]

You said “Patient” Good to see this Doc!

 

[drf256]

I’m pretty darn SLOW. Got the band cut and nothing else. Next weekend, the base.

 

[singinwoodwackr]

Are we there yet? Are we there yet?

 

[pavel408]

I’d doing a good friends 400. The saw was NIB when I got it.

Is it normal that a jug on a new saw has got "used patina" (compare to the flywheel) - besides the color (or is it some sort of special surface treatment?) also scratches?!

 

[Motorka]

Patina - I was told that this is recycled aluminum.

 

[drf256]

View attachment 478913

Is it normal that a jug on a new saw has got "used patina" (compare to the flywheel) - besides the color (or is it some sort of special surface treatment?) also scratches?!

They all look like this. I bet it’s oxidation after the casting. Good eye. This saw is 100% brand new.

This patina probably explains why different jugs look different. Mahle have this color. KS and Gillardoni are much brighter.

This is the jug. It has some other colored marks on it, and had a blue wax mark (not shown) on the PTO outer transfer.

 

[drf256]

I stand corrected. I only see a Stihl brand marking cast on the jug. It does have the typical Mahle patina though.

Mahle are much easier to cut vs KS jugs. KS are a harder alloy and more commonly have plating that’s harder and extends into the ports, at least in my limited experience.

Here’s another wax mark. Must be some type of sign on the assembly line.

 

[Duane(Pa)]

I stand corrected. I only see a Stihl brand marking cast on the jug. It does have the typical Mahle patina though.

Mahle are much easier to cut vs KS jugs. KS are a harder alloy and more commonly have plating that’s harder and extends into the ports, at least in my limited experience.

Here’s another wax mark. Must be some type of sign on the assembly line.
View attachment 478915

Maybe like the A, B coding back in the day? Curious how the jug date compares to manufacturer date on handle

 

[Duane(Pa)]

Patina - I was told that this is recycled aluminum.

Hard to find a virgin these days! I remember when engines were made with the good stuff, and brake rotors were of unknown origin (rusting in a few days on a parked car).

 

[ferris]

Thx for a Build thread

 

[jacktheripper]

I’ll soak up whatever build threads @drf256 can muster. I’ve read them all several times over.