Basher
Pinnacle OPE Member
- Local time
- 10:56 PM
- User ID
- 552
- Joined
- Jan 16, 2016
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- 1,322
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- Location
- Canada

The best running saw will be the one with the best numbers at the best squish you can get without machine work.
The 10mm saws have a lighter and weaker crank/rod. There's a reason Stihl changed the pin size, it wasn't to waste money as a corporation. The 10mm have a cult following because they did run better than the 12mm from the factory. Was it EPA rules? I'm not sure. I haven't heard of many failures though.
The 12mm saws have wider ports and the piston has wider skirts. Putting a 10mm piston in a 12mm jug can/may freeport or catch a ring. The 10mm Meteor piston has the same skirt widths as the 12mm Meteor and oem piston, but the pin bosses are too far apart-this allows for side to side movement of the pin bearing. Freaks some guys out, but I haven't heard of a failure. I believe a meteor 10mm slug will allow any jug to be used on a 10mm crank.
Personally, I'd sell the 10mm slant fin jug to someone because it's worth more. I'd pic the decomp jug because I'm getting older and I like a decomp now. I have a feeling in a few years, I'll like the decomp even more.
One of the best running 044/440 I have ever done was a straight fin decomp jug with no porting at all. I took .010 from the chamber and then cut the base for an .020 squish with base gasket. Added a flywheel side deflector and advanced the timing by .025 of the key. I didn't time the jug but I sure wish I had.
You can get someone here to do that machine work for very little cash and do the muffler and advance yourself.
I believe cylinder condition plays a larger part in performance once all the cylinders have seen a lot of hours= wear. I have early slant fin cylinders with thousands of hours on them and I can tell you a new straight fin cylinder with new piston and rings will produce more power than those old cylinders even if they have a new piston and rings put in them. The rings have a more difficult time sealing in to a worn bore and just don`t make the same power they did when the cylinder was new, this is just from personal observation building and running many dozens of these 044 saws. My 044`s with new OEM slant fins are a bit more peppy than the used stock straight fin one I keep for comparison but it doesn`t take much work to make a straight fin to match it.