Need help to ID a Stihl Mahle cylinder

[Roanoker494]

Recently received a piston and cylinder and I am hoping someone can help me ID. The numbers on the cylinder are Mahle 52ZN12, it has the impulse line hookup on the rear cylinder lip and has about a 2" bore. The spark plug sticks straight up out of the top of the cylinder, versus leaning to the back like on my 042. Sorry I can not do better on a bore measurement because I can not find my caliper.

Thank you

 

[Roanoker494]

Here are some pictures

The other side of the piston has the numbers 052096 and what looks to be a $ symbol. There is also H12 stamped on the top of the piston, as well as the A--> marking the piston direction and a B that matches the stamp on the top of the cylinder.

 

[SawTroll]

I would guess that one is for a very old model, but I really don't have a clue.......

 

[atvguns]

I would guess that one is for a very old model, but I really don't have a clue.......

I agree

 

[Roanoker494]

As of right now I am leaning towards a stock 056. I got this thinking it was a 52mm 048AV top end, but the plug hole on a 042/048 is angled towards the back of the cylinder. The piston from this top end will fit on my connecting rod but bottoms out against the crank counter weights. After doing some research I have found that the 048 had a 36mm stroke and the 056 had a 38mm stroke, this could explain why the piston will not clear. This piston is made for a saw with a 2mm longer stroke.

 

[Jacob J.]

Looks like early 045. The 056 has the impulse nipple in the case.

 

[Roanoker494]

Looks like early 045. The 056 has the impulse nipple in the case.

That was another one that I was considering but I could not find a record of a 045 with a 52mm bore. The stock 045 had a 50mm bore and the super had a 54mm bore.

 

[Jacob J.]

That was another one that I was considering but I could not find a record of a 045 with a 52mm bore. The stock 045 had a 50mm bore and the super had a 54mm bore.

The earliest 045 had a 50mm bore, with a 1mm ring on top and a 1.5mm ring on bottom (Bosch points ignition.)

The next 045 (AV) had a 52mm bore with two 1.5mm rings and the Bosch points ignition.

The next 045AVE and AVEQ had the 52mm bore, two 1.5mm rings, and electronic ignition (Bosch.)

The final was the 045 AV Super. 54mm bore and electronic ignition (Bosch.)

 

[Roanoker494]

The earliest 045 had a 50mm bore, with a 1mm ring on top and a 1.5mm ring on bottom (Bosch points ignition.)

The next 045 (AV) had a 52mm bore with two 1.5mm rings and the Bosch points ignition.

The next 045AVE and AVEQ had the 52mm bore, two 1.5mm rings, and electronic ignition (Bosch.)

The final was the 045 AV Super. 54mm bore and electronic ignition (Bosch.)

That has settled it in my mind, it is a 045 p/c. To further support that theory there is a 45 stamped beside the plug hole.

 

[Jacob J.]

That has settled it in my mind, it is a 045 p/c. To further support that theory there is a 45 stamped beside the plug hole.

The only other one it could be is 048, and as you say- those cylinders have an angled plug hole and the top is shaped differently.

 

[Roanoker494]

The only other one it could be is 048, and as you say- those cylinders have an angled plug hole and the top is shaped differently.

Unfortunately it isn't the 048, man I wish it was. Back to looking for a 048 p/c or a new 042 piston.

 

[rupedoggy]

JJ my research shows the 045 had a 50 bore in the av and ave and a 54 bore in the super. the only 52 bore was a 056 av. Some early saws had points so maybe they had a pulse nipple on the cylinder also and later changed to the case mount. That cylinder looks like that family for sure. Mike

 

[Roanoker494]

JJ my research shows the 045 had a 50 bore in the av and ave and a 54 bore in the super. the only 52 bore was a 056 av. Some early saws had points so maybe they had a pulse nipple on the cylinder also and later changed to the case mount. That cylinder looks like that family for sure. Mike

Either way the P/C is useless on my 042. 056 was my original thought until JJ gave me the information on the different 045 versions. Mike Acres did not show the different versions, but again the P/C is still useless to me.

 

[Jacob J.]

JJ my research shows the 045 had a 50 bore in the av and ave and a 54 bore in the super. the only 52 bore was a 056 av. Some early saws had points so maybe they had a pulse nipple on the cylinder also and later changed to the case mount. That cylinder looks like that family for sure. Mike

Mike-

There was an 045 with a 52mm bore. I have two of them at home. One just says "045 AV" and the other says "045 AVE".

 

[Roanoker494]

Mike-

There was an 045 with a 52mm bore. I have two of them at home. One just says "045 AV" and the other says "045 AVE".

You do know that the 056 p/c will fit on a 045? Is it possible someone had done a swap on your 045 saws before you got them?

 

[sefh3]

I have a cylinder off a 048. I'll go get a picture of it soon and post it up.

 

[Roanoker494]

I contacted the feller I got the p/c from and oops, he sent me the wrong one. He has the right one and it will be on it's way Monday morning.

 

[Jacob J.]

You do know that the 056 p/c will fit on a 045? Is it possible someone had done a swap on your 045 saws before you got them?

Yeah, after 21 years of working on saws and being a certified technician in Stihl, Husky, and Jonsered dealerships, I've pretty much seen everything possible.

I actually have all the printed technical bulletins on the 045/056 series and they document all the changes, including bore sizes on both models. What you guys see in IPLs is not gospel, especially since saw manufacturers contract third parties to produce IPLs.

My two saws appear to be all original. There's no "molestation" marks on the cylinder base fasteners.

 

[jockeydeuce]

I'm the dumb a$$ that sent Johnnie the wrong P&C!!:bang:

I've got the right one going out to him on Monday.......

 

[sefh3]

That cylinder looks alot better for an 048. Here is the one I have with a few broken fins. If your interested in a backup or want to try your porting skills for one, PM me.