Have Built two,,,,
Search my post all the info is there,,,, tek9tim has one also
Both are kick ass saws,,,, I have one I ported with the Baileys aftermarket 046 kit,,, and an OEM one that Dean and I put together in the River's (RR2) PNW Great chainsaw adventure thread last spring,,,, It is my favorite saw,,, the 044/046 strokes are the same so it is just a matter of making the fit up changes to squeeze the 046 jug into the 044 chassis
Basically as Lakeside told ya,,,, gotta machine the sides of the 046 cylinder base to match the 12mm 044 crankcase,,,, {place the 44 & 46 cyls, together machined face to face,,, scribe a line on the overlap and remove material till the sides match} dont install your piston until all the cyl fittament mods are completed
Then slot the base mount holes @ 45* into the center of the bore (diagonally) an Old chainsaw file works well, dont remove any more material than you need to as the 044 cyl. base fastener is 5mm and slightly smaller spacing center to center and the 046 jug is sized for a 6mm. You can check that when doing the step above.
The Flywheel side cyl. transfer @ flywheel interface needs a "few" hundredths removed,,, (flat/half round bastard!!!!) to clear the backside outer edge of the flywheel or you can radius that edge on the flywheel a bit more either way works...
The 046 exhaust port flange is about .35-.40 in. longer so you will have to build some spacers to fill the gap @ the bottom muffler casing to crankcase fit area,,,when you are installing the muffler casing you will see what I mean You can use a 5/16 or 3/8 nut on each bolt hole or even stack washers if that's all you have
the front air dam on the top 044 shroud needs to be trimmed out,, 046 cyl fins are just a bit taller,,,, dremmel or an old carbide cutter will get er done,,, or trim the cylinder fins where they hit
2000ssM6,,,,, dont take offense,,,, installing sealer in lieu of a gasket does boost compression,,,, However,,,that does not constitute "Decking a cylinder" theres a little more to it than that,,,,
and if you choose to do so make sure you check your squish,,,
If ya need more info send me a PM
River