I have had spitting. The best remedy for me was to add more rubber bands. I usually use two. Diamond tip tubes. A hard rubber grommet and replace after every session. This thing chews them up. I retuned it to hit soft without bogging down on my thumb. Somewhere between 3 - 3.5 mm stroke. Tighten up the two set screws after tuning. Run no faster than 6.3 V. That is all.