Hi I have a Karcher K5 55 Jubilee wich not start all the time. Some days it work but today it refuse to start. Sometimes after it start the pressure is very low... I used it maximum 15 time in 5 years

SOURCE: Karcher electric pressure washer

Dear mike husband,
One reasin for this fault could be a damaged lance or turbo lance. Try by replacing with new ones. If the problem is not solved, then the fault is due to a damaged spill valve. The spill valve could easily be damaged by using not suitable chemical or detergents. After using chemical detergents, one must always rinse the machine by passing pure water. The spill valve could also be damaged by leaving the machine for a long time with pressure in the system. One must never store such machines with pressure still inside. Always press the gun before storing.
Well the solution is to change the spill valve with a new one. In some cases even faulty suction valves can give this problem. But in the majority of cases it is the spill valve.
If you do not know how to fix this problem, it is better to be done by an expirienced technician.
Regards,
MG.

SOURCE: Karcher G 3000 BH Engine Pumping Problem

This may not be a motor problem. It sounds like your pump is not working properly and the motor is just following the pump. First thing to do is check for leaks in the pump, wand hose, gun etc. It may also be a blown water seal inside the pump.

SOURCE: karcher pressure washer works only with low pressure

The inlet screen orientation is of no consequence. Either way should work fine. Check two things...

1) Many of the spray nozzles have a high and low setting at the tip of the wand (where the water comes out). See if your nozzle has any "Push-Pull" movement (with the unit turned off). If so, it might be set in the "LOW" setting and needs to be changed.

2) Located on some SIDE MOUNTED pumps is a "Variable-Volume" adjustment. It may need to be turned to increase the flow and should be marked with a plus (+) and minus (-) along with direction arrow.
NOTE: If your pump is mounted on the bottom of your engine you will not have this adjustment.
Hope this helps!

SOURCE: Manual needed for K3.65 Jubilee Karcher

hi here is the link for manual
http://www.karcher.com/int/Service/usermanuals.htm?translationmode=&ACTION=SELECTTEILENR&ID=16017510&SELECT=Select+Product

SOURCE: low pressure on the pressure washer

Most likely your "O" rings or seals have gotten hard and are leaking. Sorry I don't know your equipment well enough to tell you how to change them but you can most likely find the info at your manufactures web site.