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Kubota kx121 cranks but won't start

steveme

Active Member
Joined
Jul 26, 2012
Messages
42
Location
usa
Occupation
Retired construction
Haven’t got this machine to start yet. I’ve basically rebuilt the whole damn fuel system and yet it doesn’t fire. I just replaced the plungers in the injection pump with no results from that either. Im definitely getting stressed out over this. Im replacing the drive belt because it seems to be loose. Once I get that done I’m going to start looking at sensors. Im just boggled that it doesn’t fire. The injectors were replaced and the compression is good.
 

thepumpguysc

Senior Member
Joined
Mar 18, 2010
Messages
7,689
Location
Sunny South Carolina
Occupation
Master Inj.Pump rebuilder
Can u unhook the lines at the pump and injectors, turn the lines around and hook them back up to the pump..remove the injectors from the head and hook them back up to the lines, outside of the head..
This way u can SEE if the injectors are firing..
CAUTION!!! the spray from the injectors WILL penetrate your skin and cause BLOOD POISONING.!!!
STAY AWAY FROM THE SPRAY..
Pay attention to the copper gasket in the bottom of each cylinder.. they have a tendency to blow out and get lost.. it’s best to take them out and set aside..
When removing AND installing the injectors USE THE BIG HEX ONLY.. otherwise you stand a chance in unscrewing the 2 half’s of the injector..

BTW.. where did u get the part number for the new p & b’s.??
Are u SURE u put the plungers in the correct way.??
 

steveme

Active Member
Joined
Jul 26, 2012
Messages
42
Location
usa
Occupation
Retired construction
Can u unhook the lines at the pump and injectors, turn the lines around and hook them back up to the pump..remove the injectors from the head and hook them back up to the lines, outside of the head..
This way u can SEE if the injectors are firing..
CAUTION!!! the spray from the injectors WILL penetrate your skin and cause BLOOD POISONING.!!!
STAY AWAY FROM THE SPRAY..
Pay attention to the copper gasket in the bottom of each cylinder.. they have a tendency to blow out and get lost.. it’s best to take them out and set aside..
When removing AND installing the injectors USE THE BIG HEX ONLY.. otherwise you stand a chance in unscrewing the 2 half’s of the injector..

BTW.. where did u get the part number for the new p & b’s.??
Are u SURE u put the plungers in the correct way.??
Thanks for replying. Yes I thought of taking the injectors out and hooking them up the way you said and is most likely my next step. As far as the plungers I ordered them from online and they came from China but it seems everything is from China now a days. The plungers were all the same as the original one and I paid hood attention to how everything came apart so I could reassemble the pump as it was. I checked the action before I placed the injector lines back on and also bleed at the injector head. The injection pump itself doesn’t have many parts that need replacing except for the plungers so I figure once they were replace everything should be fine with them. The spray coming out of the injection pump looks good. As for part numbers I went off of what was printed on the parts or at least the ones that had numbers which the plungers did. I’m going to do as you suggest and yes stay away from the spray of the injectors. If the injectors don’t spray what does that mean? Compression is good in all cylinders
 
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