ZX 50 U bogging

[Sam735]

Hi all I have a 2002 Hitachi ZX 50 you same as the deer 50 ZTS. I have an odd problem going on where when it warms up after about an hour or so the engine will sometimes bog under hydraulic load, I checked the basics like fuel filter lift pump I Put new hydraulic fluid in it. Because it was slightly milky not too sure why the suction filter seemed quite clogged cleaned all that out but still no luck. It will only bog when it is fully warmed up and will not do it when it’s cold. When it bugs it is generally when using a couple of hydraulic functions at once but not always and if you hold it for long enough it will still but if you move a control slightly, it will go back to normal. Any help greatly appreciated. Not sure where to look next.

 

[Simon C]

How many hours on the unit? Will it run off of a Jerry Can of fuel ? If you disconnect the line after the fuel filter will the fuel just pour out for like more than a minute. Will it run okay with the fuel cap off.
Any codes on the monitor. How long have you owned this unit. Will the fuel pump stay in full fuel when it starts to bog.
Simon C

 

[Sam735]

10000 h haven’t tried running off Jerry can not sure if it runs with the fuel cap off I assume it would no codes. I’ve owned this digger for a few months now and it’s been an ongoing problem. My next guest would be a relief valve sticking or something like that.

 

[Simon C]

You will have to start somewhere, test and draw conclusions from the tests, not firing off a parts cannon and still no go. Find out from dealer where all the fuel filters are including if there is any screens in a transfer pump if it has one. Banjo bolts sometimes have screens, not sure exactly what you have.
Simon C