I have owned a lot of these 1127 series Stihl saws. You need to add the 029 and 039 to this list to make it complete though. The 029 was a complete DOG. Nothing I did could get that one running well. Underpowered boat anchor no matter what. The 290 was way better, but needs the original more open muffler to make it run right. It is still somewhat anemic though. And vibe prone. The 290 and 039/390 had high vibration. The 310 was the sweet spot of this line. Lowest vibration of the lot and they ran well. I had maybe a half dozen of them and over a dozen of the 1127 line of saws in all. But even with all the tweeks that I know to mod these guys, I could never get a 310 to run as strong as a stock 361. All timed cuts run and tested with the same B&C in the same wood. So I moved on to the pro line of saws. The 026, the 360 and 361, the 044 and 440, 066 and 660. If I run across cheaper 1127 saws I will buy them. The last 310 I bought was $125 at a pawn shop. That was a steal. But for the most part here they are way overpriced on the used market. I can typically get a good 026/260 for less than the price of a 290. Most listings for 290s here on CL are $300.
Two things you should do on any 1127 saw. One is open up the muffler to the original stock size. Then re-tune your carb to fatten up the mixture. You will get a noticeable power improvement with that and restore the saw to its stock design w/o over-stressing anything. The other is to replace the spur drive/clutch drum with a stock 036 rim drive and drum. Not the beefier 360 drum, the early model smaller needle bearing one. That fits the 1127 saws perfectly and makes them more like a pro saw. You can then swap rims and your chains will run and wear a lot better.
Porting them is easy when you have a whole pile of cylinders to go through. The transfer ports need more work then the saw has value in reality. Having a drop in jig with a stop mounted on the mill could make these very easy to port. Might try that that this winter and see how much time we waste there.
