Same saw.
After they are modded I'm sure they are more sensitive to tune. Most guys fugh it up rather than get it tuned correctly. The "trick" is to use a tach....find the rpm limit, go a bit leaner than "against the rev limiter". That not something that's black or white.....it's a learned process that can be interpreted a bazillion ways evidently. On the low side, you have to BARELY turn the screw, then use it a little while before moving it more. It's not a quick or easy process to get it back right after someone gets it way out of tune. Usually, the saw will seem fat on the low side when first started.....and as a result, it will idle too low. Then the user opens the throttle plate more.....then it idles too high once it hot. So....they fatted up the low side to make it idle down. Next time they use it.....same thing. Before long, they have the throttle plate WAY too far open, and low side adjustments do nothing.
I've bought back three of them over the years. Retuned.....and resold.
I couldn't work in that environment. I'd kill a mfer.