Which 046 did I just buy?

[JonCraig]

Bought a basket case 046 today & am trying to learn more about it. I found a Stihl TSB talking about a change to the jug. Was this the upgrade from 10mm to 12mm wrist pin?

My saw is 1 33 908 445. If I'm reading correctly, I'm the old style, then?

You who know better than I, am I getting my hopes up? Probably just a run of the mill 046, huh?

Thanks in advance!

--JC

 

[JonCraig]

Wait... was it 044's that had the different size wrist pins?

 

[Mad Professor]

That saw needs a bath!

 

[JonCraig]

That saw needs a bath!

Most definitely! Just picked it up this afternoon but had already promised my 5 year old that we would go on a "pirate treasure adventure" before it got dark. You know which one took priority.

 

[blsnelling]

The 046 never had a wrist pin size change.

 

[blsnelling]

View attachment 585528 View attachment 585529 View attachment 585530 View attachment 585531 View attachment 585532

Date Purchased : 05/22/1996
ASHLAND CITY, TN 37015

 

[JonCraig]

The 046 never had a wrist pin size change.

Was there something with D-shaped ports & more aggressive timing? When did that stop?

Acres lists the model starting in 1995, & this one tracks to 1996. Very cool, thanks @blsnelling !

 

[drf255]

The 046/460 has the most factory variants of the cylinder than any other Stihl model I've encountered.

My understanding was that the earliest cylinders were the coveted "D" chamber jugs which have a smaller D shaped combustion chamber and are supposed to be more aggressively timed than there Hemi chambered counterpart.

I don't follow that service bulletin that states that the old 046 jug was still available and the low comp version.

I prefer the Hemi chamber for porting myself. Keeps compression down.

 

[JonCraig]

So it's the profile of the combustion chamber, I see.

What you're telling me is to pull the jug and post pictures?

 

[drf255]

So it's the profile of the combustion chamber, I see.

What you're telling me is to pull the jug and post pictures?

Who doesn't like pics of jugs?

 

[JonCraig]

Well what do you know? It looks like a "D" in there! None of those lines are transfer--just wear. I can't feel any of those marks with a fingernail and there's still original cross-hatching in a few spots. Looks like it was just used a lot, but never had any big failure. My guess is when the handle broke the saw got put out by the wayside.

The saw needs a new tank, all the plastics, a clutch, clutch cover, bar & chain... I usually buy more or less complete saws of CL, but the price was right on this one, and I like a challenge. Purely financially, it probably makes more sense just to part out what's left, huh? How much is that jug worth?

 

[blsnelling]

It's not the D-shaped CC that makes them run so well, but rather the port timing. You'd need to put a degree wheel on it in order to verify that. Reported, only the first year saws had the optimal port timing.

 

[JonCraig]

You're right... the May '96 serial number is a good indicator, but it could have been replaced with a later D cylinder at some point in its life.

Now to go read up on degree wheel stuff. Never done it before. I seem to remember you having a thread on it, Brad? To the search bar I go!

 

[blsnelling]

I don't know if I ever did a thread on degreeing a saw. I'm pretty sure @Mastermind did.

 

[JonCraig]

My first time using a degree wheel, so let me know if I'm way off.

Zero'd the wheel at TDC.

Intake JUST starts to close at 14 deg after TDC.

Intake totally closed at 73 deg after TDC.

Exhaust JUST starts to open at 103 after TDC.

Exhaust totally open at 180 (which is BDC)

Upper transfer was really hard to measure. I stuck a soft piece of wire through spark plug hole and followed piston up. I felt it go into transfer, then when the piston "hung" it, I read the degree wheel. I got 131 degrees after TDC. Which (given the width of the wire), means it would have opened a hair earlier.

Do those numbers even make sense?

Thanks!

 

[JonCraig]

Just tried the transfer again w/ a flashlight through the exhaust & got 120 degrees.

 

[blsnelling]

That's much more like it. That gives you 17° of blowdown. I've seen then with as little as 15°-16°. That'll be a good runner.

 

[JonCraig]

Would that drop onto my MS460?

 

[blsnelling]

Yes. They're the same saw minus fuel/oil caps.

 

[drf255]

Looks like you got yourself an excellent jug there. Have you measured squish?

I'd say that jug is worth $100 to the right fellow.