If in doubt and if you have modded your saw, start by screw the low and high blend all the way in (close) and carefully count the turns so you know exactly what it was to begin with. That may be like 3/4 to 1-1/2 turn...
- Turn you high rpm blend 1/4 out from its original position (if it was 1 you go to 1-1/4, if it was 2 go 2-1/2). Use 40:1 fuel/oil mix or add a little extra two stroke oil in the fuel if you want to be extra safe.
- Find a good representable log to cut - something similar to what you are used to cut so you know approx how your saw will do that.
- Fire up, let it warm up a little and start cutting; when you add a slight force to the saw to cut through the log - it should run clean.
Now if you stop adding the slight pressure to the saw or hold it back a little - it will stop progressing through the log and it will increase rpm and start to run free, at this moment the saw should start to fourstroke. This sounds like it is not running clean, it kinda skips a beat every now and then and that limits the rpm. Add pressure again - it starts to cut and it runs clean, release the pressure again - it increases rpm slightly but then starts to fourstroke.
- If it does not run clean in the cut - it is too rich, lean the high blend (screw in). If it does not start to fourstroke when you release the pressure from the cut and it increases rpm excessively - enrich the high blend (screw out).
You will get a feel for it, what sounds healthy for the saw. You do not need it to run clean unless you actually cut through wood.
When happy with it, you look at the idle. Try turning the low blend in or out gradually untill you hear a change in rpm. You should be in the middle between the lowering rpms at too rich or too lean. Finally hit the throttle - it should accelerate effortlessly without starvation, if it lingers - try to rich the low blend slightly first.
You wont get it perfect like this - using a tac. A tac is theoretical, if you modded your saw you are now in the real life realm.
