serg, you may want to richen up the hi and lo needle about 1/8 turn. See what happens.. the 1 1/2 turns are starting points but are needed to be adjusted a bit depending on each engine/plane/gas/environment/etc. Try it and see what happens. I worked in the chain saw industry for 10 years as a mfg rep.. so I have a little insight into the carb thing..... just wanted you to know.. BobH.