[APWS]

hi guys,
what makes a machine jerk when pulling the trigger? when I release the gun it runs smooth but as soon as I pull the trigger it starts jerking like a pulse, it's a gx390 with 19.2 litre pump, is air getting in somewhere ? I recently changed the unloader valve to a k5 and adapted the pump to a suck & return system,
thanks. 

[Don Kee]

hi guys,
what makes a machine jerk when pulling the trigger? when I release the gun it runs smooth but as soon as I pull the trigger it starts jerking like a pulse

I think someone needs 'the talk'...

[Roger Oakley]

Re-check all you have done with the replacements, as it does seem from what you are saying it is drawing in air from somewhere.

[chris scott]

Re-check all you have done with the replacements, as it does seem from what you are saying it is drawing in air from somewhere.

Or a partially blocked nozzle.

[cleaning4usussex]

Mine done that for a while it's also started stalling when I let go of the trigger I've had nothing but problems with mine and it was brand new!  I've done probably 20-30 jobs with it and it's messed about every time doing something strange problem is every time goes wrong it's half a day wasted driving to london

[BDCS]

Mine done that for a while it's also started stalling when I let go of the trigger I've had nothing but problems with mine and it was brand new!  I've done probably 20-30 jobs with it and it's messed about every time doing something strange problem is every time goes wrong it's half a day wasted driving to london 

Why does taking a pressure washer for a drive to London help ? I'd mess you about if you kept making me go to London 

[Kenny83]

2 small a nozzle? Wrong k unloader? (needs to be a k5.3 for 19 lpm, not 5.2 or 5.1 etc) blocked valves?  is it a jerk or shudder?

[BDCS]

5.2 is 16 - 25 ltrs

[APWS]

2 small a nozzle? Wrong k unloader? (needs to be a k5.3 for 19 lpm, not 5.2 or 5.1 etc) blocked valves?  is it a jerk or shudder?

it's a jerk Kenny, and bdcs is right k2 is 16 - 25 ltr, i'v put new valves in the pump, will check all my conection & nozzles,
thanks.

[chris scott]

Fit a new unloader