Stihl 009 Piston Identification (Help!)

[TimmyC]

Hello Everyone-
I've found this site useful for years but never had the need to post myself before. Well here I am!

I'm working on a Stihl 009 that has a scored piston. Based on a Stihl parts manual, I see there is a 36mm and 38mm bore. If I understand, the 38mm is the 009L and is labeled as such on the side. My confusion is this: I have a saw labeled 009 (no L) that I measure as 36mm bore and piston. It has a single ring. All good so far. HOWEVER, it mounts using four 35mm screws with a flange base which seem to be characteristics of the "L" version. I'm hoping you fine folks can help me understand what I'm seeing and exactly what piston I need to order. Thanks in advance.

 

[HarleyT]

Here is what is in the mediacat. Unfortunately it doesn't have any bulletins concerning this.

 

[HarleyT]

Here is the bottom of the parts list numbers.

 

[TimmyC]

Thanks HarleyT. This is reprinted from the Stihl document I'm referencing.
Unfortunately, it doesn't reflect my reality.

My bore is 36mm by my caliper but everything else about the design matches the "C" cylinder (your first image) right down to the 4 35mm long bolts (instead of 2@25mm in the "D".

This site: https://************************/forums/threads/stihl-009s-anyone.7730/ includes the tantalizing phrase "They are 36mm but they are 4 bolt for the newer style(gray) saws. My old orange ones are 2 bolt." which would seem to be my case (mine's grey too) but part numbers or official mention of this alas I can not find. That's why I'm asking on here.

 

[HarleyT]

It shows a serial number break on the older ones. What is your serial number?

 

[TimmyC]

Serial Number: 231506192 (it's all white in color)
Thanks.

 

[Mad Professor]

Are you sure it's 36mm? Measured through the ex port or with cylinder off?

 

[TimmyC]

Are you sure it's 36mm? Measured through the ex port or with cylinder off?

I feel so. Here are pictures of the measurements.

Notice it also shows the single ring per the 36 yet it has a flange per the 38.

 

[Mad Professor]

Does seem to be 36mm.

The IPL has some strangeness going on. On the discontunued 36mm parts page, it shows both 1 and 2 ring 36mm pistons. Several part# 36mm rings, and a 38mm ring?

I wonder if your saw could take a 38mm cylinder, or even a 40mm 012 cylinder. IPL shows same gaskets.

 

[Lightning Performance]

Saw a listing that had 009 as the little motor.
The 009L and 011 appears to be the bigger bore. Beyond that itself for parts fitment... I have no clue. That probably doesn't help much.

 

[HarleyT]

Does seem to be 36mm.

The IPL has some strangeness going on. On the discontunued 36mm parts page, it shows both 1 and 2 ring 36mm pistons. Several part# 36mm rings, and a 38mm ring?

I wonder if your saw could take a 38mm cylinder, or even a 40mm 012 cylinder. IPL shows same gaskets.

Back then, when they made any changes, it was not a crisp move all at once usually, but one change here, another change there, and the transitions don't always match up with the current ipls. Unfoturnately the tech. bulletins didn't make it on the mediacat, as there would be the answers.

 

[StihlSolo]

I have attached 4 pages from my original 1984 009 IPL, with notes and highlighting. Hopefully these will clear up any confusion. The IPL shows 36mm piston 1120 030 2009 and ring 1120 034 3000 will fit a 36mm 4 bolt cylinder. You should use new 1120 029 2302 base gasket(s) and 9462 650 0900 (or equiv) circlips.

In this 1984 IPL Stihl had a complete top end kit with new 4 bolt 36mm cylinder, piston, ring, piston pin and circlips at part number 1120 020 1203 (without gaskets). The IPL did not show a part number for a new 36mm 4 bolt cylinder alone. Hopefully you can clean up the cylinder you are working on.

What is weird about this IPL (and most copies/versions of it) is that parts for the 009L (aka 009LEQZ) are also referenced. If you are looking for 009 parts only, don't get confused by these references.

 

[StihlSolo]

I feel so. Here are pictures of the measurements.

I just saw your full sized photos. You need to stabilize the connecting rod bottom end to keep it from moving sideways. The bottom end bearings are loose uncaged rollers and will drop out of place if the connecting rod bottom end slips sideways. It's a pita to reinstall these roller bearings.

In the past I used wood popsicle sticks jammed in through the intake opening (with carb & reed plate taken out). Jammed down on both sides of the connecting rod to keep it from moving. Usually it takes a few sticks on each side.

 

[TimmyC]

My sincere thanks to StihlSolo and everyone else who helped me sort out this saw.
I really appreciate your help in solving this pickle my friends!