Pressure Washer

[stefan szoka]

Not quite woodwork, but has anyone had a problem with a pressure washer in that it 'oscillates'.
Instead of running at constant speed & pressure, the motor speeds up and slows down at a frequency of around 2 Hz
Any cures ?

Stefan

 

[Scott]

You sure it's getting enough water Stefan? There's no inlet filter that might be blocked?

 

[stefan szoka]

Yes getting plenty of water, in and out.

Stefan

 

[Travis Byrne]

Hello Stefan

If this is a gasoline engine, it sounds like the carburator needs some adjustment. Is there an anjustment screw on it? If so, get the machine running with the water spraying and adjust the screw slowly outward. No more that a half turn total. If this doesn't help, go back to orig. position and slowly adjust inward. This worked on lawn mower that was pulsing back and forth.

Travis

 

[stefan szoka]

It's an electric presure washer. Without the lance connected it runs o.k. Fit the lance and it starts pulsing.

Stefan

 

[DaveL]

Stefan,

I would take the lance off and try to back wash though it, it sounds like there could be something moving behind the jet blocking the flow?

 

[tibbs]

It sounds like the pump is cavitating - i.e. its not getting enough water to it (or not getting water at a high enough pressure to maintain the flow rate it needs) - even the little ones move a lot of water.

I had a similar problem with a small Karcher petrol driven washer with no hose supply nearby - the manual said use 3/4" hose when drawing water from a water butt etc - I didnt have any at the time so I tried 1/2" with the water butt 6' up in the air lashed to the front bucket of a tractor - plenty of pressure I thought - no way - the washer fired a good jet for a second then quit for a second or two with appropriate variations in engine pitch etc., then repeated again. 3/4" hose fixed the problem straight away.

If your washer has only just started doing this with the same setup then I'd guess its either a partially blocked filter (as others have said) or maybe your mains pressure is down at the moment (or maybe the pump is about to pack up )

Richard