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Hitachi 120-2 questions and anwsers

bdward

Active Member
Joined
Sep 10, 2014
Messages
29
Location
alaska
I just got a EX100-3 that may need the conversion kit but I haven't done any of the diagnostics yet. There is NO electrical control of the throttle and to even start it and I need to hold the pump throttle control with a wedge to set the speed. I ALSO HAVE ONE OTHER ISSUE I HAVEN'T HEARD ABOUT IN ANY POST. I don't have any electric control for track speed. It's fixed at slow speed. Is this part of the problem a conversion kit will fix? Your responses are appreciated.
 

SoutheastSavage

Well-Known Member
Joined
Sep 27, 2020
Messages
46
Location
Kasaan Alaska
so With your throttle control, conversion won’t fix. You can check the EC. Motor throttle motor to see if it’s getting power if it is make sure your throttle cable isn’t bound or seized. ?? And if your machine functions fine as far as not bogging when you use hydraulics I wouldn’t do the conversion. If everything works fine except throttle and track speed. I would try to track those issues down. If machine does bog and has other issues. Throw a manual throttle in and get a conversion kit on it
 

bdward

Active Member
Joined
Sep 10, 2014
Messages
29
Location
alaska
so With your throttle control, conversion won’t fix. You can check the EC. Motor throttle motor to see if it’s getting power if it is make sure your throttle cable isn’t bound or seized. ?? And if your machine functions fine as far as not bogging when you use hydraulics I wouldn’t do the conversion. If everything works fine except throttle and track speed. I would try to track those issues down. If machine does bog and has other issues. Throw a manual throttle in and get a conversion kit on it

Thanks for your response. So far by jamming a screw driver between the pump throttle shaft & stop to speed up the engine, I seem to have proper hydraulic operation. Is the conversion kit mainly to replace the computer signals that maintain the proper pump stroke during a load and nothing about the throttle motor control? If so I see your point. I'll check those functions. Fortunately I have the books though their sometimes hard to follow. Need to get on this as it's starting to cool down here in Delta Jct. - Thanks again
 

SoutheastSavage

Well-Known Member
Joined
Sep 27, 2020
Messages
46
Location
Kasaan Alaska
Yeah your right there. I would suggest checking for power at throttle control. If there is power and nothing is working consider buying a new one. I think they are about 150 bucks on eBay. Or Friday parts.
 

SoutheastSavage

Well-Known Member
Joined
Sep 27, 2020
Messages
46
Location
Kasaan Alaska
This is the instruction for the conversion kit that I have been able to find. I haven’t installed my conversion yet. But I plan to soon
 

Attachments

  • Mounting instruction for Conversion Kit.pdf
    1.4 MB · Views: 123

SoutheastSavage

Well-Known Member
Joined
Sep 27, 2020
Messages
46
Location
Kasaan Alaska
Haven’t been on in awhile and I just wanted to let everyone know that I did the conversion on my 120 today.
After conversion I experience no bogging and plenty of power. I haven’t ran it for a long period of time but so far am very pleased. Conversion took about 3-4 hours and was fairly easy to do. Instructions are not great but good enough. I took some pictures of my work today here they are and cheers everyone that helped and gave me info and pictures it helped a lot
 

JDCrow

Well-Known Member
Joined
Sep 25, 2020
Messages
125
Location
Redmond, Or
Still and option for me. Still dealing with boom up. Thanks for pics. It does look pretty straight forward
 

SoutheastSavage

Well-Known Member
Joined
Sep 27, 2020
Messages
46
Location
Kasaan Alaska
Yeah after running machine a little I noticed that my stick in. Is very slow and sometimes can only do one function at a time can’t boom up at the same time. Thinking about putting more shims in conversion any input ?
 

LACHAU

Senior Member
Joined
Aug 11, 2009
Messages
976
Location
Saigon, Vietnam
Yeah after running machine a little I noticed that my stick in. Is very slow and sometimes can only do one function at a time can’t boom up at the same time. Thinking about putting more shims in conversion any input ?
  1. "..stick in. Is very slow" If single action, It relate to "DIFFERENTIAL PRESSURE CONTROL" to increase pump flow.
  2. "..can only do one function at a time can’t boom up at the same time". It relate to "PRESSURE COMPENSATION PROPORTIONAL SOLENOID VALVE" or we can say that is "FLOW SHARING PRINCIPLE".
EX100_EX120-2 Compensation Hydraulic Circuit.png
 
Last edited:

LACHAU

Senior Member
Joined
Aug 11, 2009
Messages
976
Location
Saigon, Vietnam
EX100_120-3 Hyd Control Explaining 1.jpg
EX100_120-3 Hyd Control Explaining 2.jpg

58VVyFK
 

SoutheastSavage

Well-Known Member
Joined
Sep 27, 2020
Messages
46
Location
Kasaan Alaska
So I’m thinking about replacing my bucket pin and bushings. I have a thumb so I’m curious on if I need to get a longer pin and how many bushings ? 6 2 on thumb 2 on bucket 2 on boom ?
 

SoutheastSavage

Well-Known Member
Joined
Sep 27, 2020
Messages
46
Location
Kasaan Alaska
So anyways I had a machinest look at my machine and is gonna build me a new pin. I have 6 new bushings coming for bucket stick and thumb. I also installed my manual throttle which was very easy to do and works great. Machine continues to work well with the conversion kit. Very happy
 
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