Water flows from pump head continously and the last time I used it oil was all over pump.is this normal ? The washer is northstar,gas driven and is not to old. the water comes from two openings in the bottom of the brass head plate.

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: Oil leaking from pump

top is a breather you may be overfull of oil most pumps you can use engine oil .drain and put in half litre or if it has a sight glass top up to low side of glass and try it out.possible your seals on way out this usually then leaks at front or gets water in.if you still have good pressure oil seals easy to do.

SOURCE: Pressure Washer Pump and Engine Stops Suddenly

The pump might be binding against the motor, causing the pump to overheat and temporarilly "seize up" and shut the engine off.
After cooling down for a brief period (5~10 mins) the engine can usually be re-started, but the overheating problem will keep coming back.

This happens when the pump either wasn't seated against the engine properly during it's initial instalation, or the pump housing wasn't machined properly and the PTO shaft is trying to drive the pump at a slight angle = excessive friction = overheating.

Try this:
1) Loosen the bolts that mount the pump to the engine just enough so that the pump can be wiggled slightly.
2) With the engine power switch in the "OFF" position, slowly pull the recoil starter rope so that the engine / pump completes about two revolutions. This helps to align the pump surface with the engine.
3) Lightly snug the pump mounting bolts in a criss-cross pattern, then slowly pull the recoil starter rope again to ensure that the pump isn't binding.
4) Finish tightening the pump mounting bolts in the criss-cross pattern (approx. 21 foot pounds torque).

The entire process should take you roughly about 10 mins from start to finish.

If this doesn't remedy your problem, then try running the engine for 20 mins with the pump COMPLETELY removed so as to isolate the components.

SOURCE: My Troy Bilt power washer (using Honda GCV160

I had a similar problem. Turns out I had left the hose disconnected and some sort of wasp built a paper type nest inside the washer tube that the hose connects to. I had to take the pump off and take apart and then cleaned it out with a screw driver. Not too easy to do but finally got it clean. Same thing happened with the hose.

So, if you haven't used it for awhile, check that there is no blockage in the hose or pump tubes. You might be able to blow it out with an air compressor.