Best to contact Alex methinks
Why don't you have a quick google before making stupid comments?
Air?Let it run on full whack for a few mins with the pole lower than the outlet of the backpack, see if that helps
Are you using a hose reel with it? if so try priming the pump first without it connected and see if it makes any difference as the longer the hose the more time it takes to get all the air out.
Its nothing todo with the rocker switch having 3 settings. is it? Always catches me out.