Fluctuating pressure I have a brand new Northstar 4000 psi, which I started using today. I start the PW and the pressure is great, then the pressure drops. If I release the trigger the problem repeatsand if I hold the trigger the pressure remains low. Very frustrating when you are trying to work.

SOURCE: Unable to start gas engine on a NorthStar pressure washer

Disassemble and clean the carb. If it ran briefly with the starer fluid then gasoline is not coming through the carb.

SOURCE: pump loses pressure after you use it a while even

looks like you need a new diaphpragm in the pump unit

SOURCE: NO PSI

have you checked to make sure that keyway is installed between electric motor and pump. also adjustment on unloader valve may be incorrect. If the big brass nut on the unloader is able to be turned by hand, then this is probably your problem (running pressure and spike pressure needs to be set and locked down using a pressure guage). does water come out of nozzle at all? if not, tip being stopped up may be the problem. trash between unloader ball and seat can also cause no pressure (usually caused by a burr left inside brass pieces during the manufacturing process). I have seen all the check valves stuck on a brand new unit from sitting on the shelf for so long, but this is usually the case with General Pumps.

SOURCE: northstar pressure washer randomly gives pressure

Hi:
You need to find the bypass (unloader) valve and grease it with a good waterproof grease. Sorry, I cannot find a pic for you

SOURCE: Northstar PW shuts off hot if washer is moved. Honda engine

Being petrol driven, it may have a mercury kill switch which puts a ground on the ignition circuit stopping the engine if you move it. Perhaps for safety in case you overturn the unit somehow.