Legal: the "trickle" you described is normal and neccesay for cooling of the packings , Honestly doesnt make sense why pulling skiers would increase the flow as you described ? Overtightening of the gland will cause the packings (which have thier own "Impregnated lube" ,some PTFE some organic animal fat ) to burnish and become less effective not to mention shaft wear , seriously leaking packings (worn or misadjusted) can cause air to be drawn into the suction and some cavitation . DPS style replacement seals are IMO best used on "perfect" pump shafts with no wear and if ever failed ,require complete jet disassembly to replace .Rope seals are easily replaced in minutes for 12 bucks