The 026 I have is in good shape for age.....it has always ran great, but sometimes it acts like it is going to die, or does die when idling....I put a new OEM carb on it, and I can get it to idle but still ain't "right" to me....I am OCD, so in reality it is probably fine for a saw of this age....
Anyway I seen were a guy said if you grind out that intake lip it will keep the fuel from "puddling " up....I didn't even run a tank threw the 026, but I will report back once I have used her more to see if it solved the problem...she does seem to be running better/stronger!!!!
Those changes should definitely help the flow. Did you have to modify the muffler at all because you funneled the exhaust port?
I haven't ported anything yet, but will be playing with a Chinese 660 build later this spring. I also just have a Dremel pencil attachment and the grinding stones with it. I've been looking at some carbide cutters on ebay to have something a little more aggressive to start with for really changing the port.
I have an older 260 that had some idle and just off idle issues. I recently readjusted the carburetor after getting an 044 from mastermind and having him explain his recommended tuning process. What I did with the 260 was a little different and is below. I can't believe I had been using it for so long running so bad. It is like a completely different saw now.
Sorry if you know this already, but I found my 260 was not as easy to set up as my 044. Here's what I did. I'm not sure if it's because the carb needs rebuilt, or because the saw is a little tired, but it seems to cut good and now idles just fine. So after reading about your experience, maybe it's the nature of the beast?
1. Set all 3 screws at 1.25 turns out.
2. Start the saw and warm it up by running at mid throttle for a little bit.
3. Once its warmed up, set the idle with the LA screw. I was getting around 2800-2900 rpms. This will probably back out a few turns.
4. Then pull the trigger slightly to get to 5-10k rpms. Adjust the L screw to improve this transition.
Mine stumbled and died quite a few times before I got it right. As I leaned up the L screw to get better transition, I had to turn the LA screw more rich to keep the idle where I wanted. So it was a lot of back and forth.
5. Adjust the H screw to whatever max RPM you trust, while holding the throttle wide open.
Don't hold it there more than a few seconds to avoid burning up the cylinder. I set my max speed at just below 14k rpms. I think that's conservative for these saw, but I'm happy with it.
6. Re-adjust the LA or L screw slightly, if needed. Sometimes adjusting the H screw will throw those off just a small amount.
