I am wondering what the safe rpm ranges should be for this saw. It has a black coil. I bought it off of my dad. He used it for falling, so it has the full wrap kit, and HD filter upgrade with a walkerized muffler mod. I’m planning on tuning using a Stihl edt 9 tach. It had an air leak but I fixed it by replacing the seals. Any help would be appreciated I’ve tried tuning by ear but I can’t seem to get it right.