I always find the answers after asking the question... Here's what I found other places here:
https://www.arboristsite.com/community/threads/echo-top-saws.335554/
https://www.arboristsite.com/community/attachments/new-echo-na_carb-adj-man_071619-pdf.765367/
Settings vary a lot, but are often pretty far out. The last one I tuned out of the box at 3 1/4 L, 2 H. Sounds like your L is turned in to far. (Ketchup)
I extrapolated this from the manual
Model: CS-2511T (C70215) (C70315) (C71915)
Carburetor Type: WT-1208
Limiter Cap Removal Tool: 91075
Mixture Needle Adjustment Tool: (flat head screwdriver)
Low Mixture needle lightly seat and turn CCW: 2-3/4
High mixture needle lightly seat and turn CCW: 1-3/4
Idle speed screw: 1 turn CCW from seated
Applies to: 12” or 14” bar
Engine warmup: (note 5) 5 seconds idle - 5 seconds full throttle - 100 seconds max, 13000 rpm max
Step 2: Turn idle speed screw CW or CCW to set RPM: 4100
Step 3: Turn low mix needle CCW to reduce idle rpm: 3300
Step 5: Turn high mix needle CW or CCW to rpm: 12500 - 12700 (NOTE 4: Turn High Mix Needle CW 1/2 turn after adjusting engine to the specified WOT range.)
Final idle rpm range (chain must not move): 2800-3600
Final WOT RPM range with std bar and chain (12700-13400)
Install new limiter caps after RPM checks: P003000010
So it seems between L = 2-3/4 to 3-1/4 : H = 1-3/4 to 2 for a starting point.