Stihl 044 10mm or 12mm

[Hamp363]

I have an 044 with the following serial #122041944. Thanks

 

[atpchas]

Should be 10mm unless a previous owner changed it. The 10 to 12 transition occurred at ser# 129583701 in 1994.

 

[L34]

Pic.

 

[Hamp363]

Should be 10mm unless a previous owner changed it. The 10 to 12 transition occurred at ser# 129583701 in 1994.

Is the jug the same on a 10mm as 12mm.

 

[atpchas]

Is the jug the same on a 10mm as 12mm.

IPL shows different numbers but that doesn't mean they can't be swapped. IIRC, the 10mm jug usually has diagonal fins on top, 12mm has side to side. Not my area of expertise, so ...

 

[Woodslasher]

There’s something about the piston ring aligner pins that’s different, you can use 1 in one but not vice versa. @huskihl may know the difference.

 

[pioneerguy600]

The jugs will swap no problem, the port shapes and timing numbers are slightly different but as far as most people would know the saw would be just fine. The 10mm piston had the ring end keeper pins slightly in different orientation from the 12 mm pistons so there were a few instances where the ring ends popped out into the intake ports of a 12 mm cylinder, one just needs to make sure the ring ends are supported by the cylinder walls when swapping parts around in any engine.The 10mm cylinders had the hottest port timing, my favorite 044 has a 10 mm case and 10 mm slant fin cylinder with some porting improvements along with intake tract improvements and of course exhaust port matching and flow improvments.

 

[huskihl]

Early 10mm saws had a K$ cylinder on them. Later 10 and early 12mm 044’s had the same identical Mahle slant fin jugs. The non-decomp straight fins were next on the 12mm 044 and early 440 and are noticeably different inside. Later 440’s had decomp straight fins

 

[Hamp363]

Pic.

Thanks for the pics. I see the difference

 

[Hamp363]

The jugs will swap no problem, the port shapes and timing numbers are slightly different but as far as most people would know the saw would be just fine. The 10mm piston had the ring end keeper pins slightly in different orientation from the 12 mm pistons so there were a few instances where the ring ends popped out into the intake ports of a 12 mm cylinder, one just needs to make sure the ring ends are supported by the cylinder walls when swapping parts around in any engine.The 10mm cylinders had the hottest port timing, my favorite 044 has a 10 mm case and 10 mm slant fin cylinder with some porting improvements along with intake tract improvements and of course exhaust port matching and flow improvments.

Okay, thanks. I purchased the saw and the previous owner put a 12mm crank in the saw. I want to try and make it original. Just wanted to make sure the crankcase serial numbers were for a 10mm saw.

 

[pioneerguy600]

Okay, thanks. I purchased the saw and the previous owner put a 12mm crank in the saw. I want to try and make it original. Just wanted to make sure the crankcase serial numbers were for a 10mm saw.

I did a couple of those crank swaps myself back around 2008, there was a thought pattern back during that time frame that the 10mm wrist pin cranks were not strong enough to withstand port work on the cylinder, that is not the case in my experience but others may vary. My 10mm saws are doing just fine with plenty of high RPM production work on them by now.

 

[Hamp363]

How do you feel about a meteor p/c replacement? Who makes a good crankshaft or should I try to find a used oem.

 

[pioneerguy600]

How do you feel about a meteor p/c replacement? Who makes a good crankshaft or should I try to find a used oem.

For me it`s OEM only as I don`t like wasting my time on cheaper alternatives and can afford the good proven stuff without hurting my wallet. Others will extol the virtues of AM parts and that`s fine if one can afford the effed reputation and time to do the job over and over.

 

[rocketnorton]

meteor in oe jug here
been a few yr, dont count tanks past bout 10, been more tho
sfsg

 

[teacherman]

Early 10mm saws had a K$ cylinder on them. Later 10 and early 12mm 044’s had the same identical Mahle slant fin jugs. The non-decomp straight fins were next on the 12mm 044 and early 440 and are noticeably different inside. Later 440’s had decomp straight fins

I have a question. I have read that the earlier K$ jugs yield more power than the later Mahle slant fins, and that the Mahles are better than the later 12 MM. jugs. Do you know if there is a big difference? Is the power gain enough to merit putting a Mahle slant fin in a late 440? I know the later carbs have limiters, so a carb switch would also be part of the upgrade. I do not want to go to the trouble of learning how to port a saw cylinder...

 

[Evan]

Best crank is 12mm and 046 cylinder. Somehow i ended up with a pile of 044 440 046 460 cylinders for some damn reason i keep hanging on to all of them.


I so far have had good like with cheap 12mm china cranks

 

[huskihl]

I have a question. I have read that the earlier K$ jugs yield more power than the later Mahle slant fins, and that the Mahles are better than the later 12 MM. jugs. Do you know if there is a big difference? Is the power gain enough to merit putting a Mahle slant fin in a late 440? I know the later carbs have limiters, so a carb switch would also be part of the upgrade. I do not want to go to the trouble of learning how to port a saw cylinder...

I’ve heard that the early ks cylinders were stronger than mahle slants, but have never confirmed it for myself. Both are indeed stronger than straight fin 440 cylinders

 

[teacherman]

Okay, thanks. I purchased the saw and the previous owner put a 12mm crank in the saw. I want to try and make it original. Just wanted to make sure the crankcase serial numbers were for a 10mm saw.

I have read multiple times that the 10 mm wrist pin proved insufficient to reliably hold up on such a powerful saw, which was why they went to 12mm. My 024 has a 10 mm wrist pin, for comparison. I'd say the 12 mm is an improvement, if it works with the case.