Kubota won't start!

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grahew
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Kubota won't start!

Post by grahew » Fri Dec 07, 2012 8:40 pm

Help! am trying to start my Kubota 722 3 cylinder but it won't fire up. I've checked the Glowplugs and all are ok, but it wont spin over fast enough? The current Battery is 17amp is this enough Amps? :cry............... any help appreciated

Tanks

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coachgeo
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Re: Kubota won't start!

Post by coachgeo » Fri Dec 07, 2012 8:48 pm

Is this a previously running engine that you've started and run before? Do you have any info on the suposed condition if not?

How is the fuel intake? Are you sure it is clear of air? You might try a cheap 12v fuel pump to use to prime the fuel system of air.

Have you checked the fuel filter(s)?

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coachgeo
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Re: Kubota won't start!

Post by coachgeo » Fri Dec 07, 2012 8:50 pm

grahew wrote:...The current Battery is 17amp is this enough Amps? :cry............... any help appreciated

Tanks
Jump start the battery with a handy running vehicle. If it substancially speeds up the engines spin then your battery is suspect.

Jump start the engine w/out the battery from a running vehicle to further test the engine itself.

grahew
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Re: Kubota won't start!

Post by grahew » Fri Dec 07, 2012 8:57 pm

coachgeo wrote:Is this a previously running engine that you've started and run before? Do you have any info on the suposed condition if not?

How is the fuel intake? Are you sure it is clear of air? You might try a cheap 12v fuel pump to use to prime the fuel system of air.

Have you checked the fuel filter(s)?

Have hand pumped fuel pressure up and have bleed each injector to remove air, can only suspect battery? what amps do you think is needed?

Mouse
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Re: Kubota won't start!

Post by Mouse » Mon Dec 10, 2012 4:36 pm

Have you tried a set of jump leads to a car battery in a running car to be sure you have tip top cranking amps available?

I've had problems starting diesels with low compression. The low compression makes the starter work very much harder and because of that cranking speed is slow and not enough to start the engine. This has sent me barking up the wrong tree several times thinking I had starter / battery issues when it was actually an engine issue.
Kubota Z482 which is plodding on with unnerving reliability. Three years so far.
1900 Diesel Bike being rebuilt with better clutch control.

penybryn
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Re: Kubota won't start!

Post by penybryn » Wed Dec 12, 2012 9:36 am

Operator's manual gives battery spec as 12V 36AH.
I second the jump-start suggestion for narrowing down the problem possibilities.

XLerate
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Re: Kubota won't start!

Post by XLerate » Wed Dec 12, 2012 6:10 pm

I don't know this engine or the details of your build but in general diesels require lots more starter cranking amps than a gasser. I prefer welding cable for the battery/starter leads, to carry the higher amperage. #6 welding cable has many more strands and much larger diameter for current carrying ability than stock wiring.

I find that diesels need lots more battery cranking amps too, no such thing as too much! In addition all terminals and connections, especially all ground connections, have to be of adequate size and must be clean and tight. Switch and starter relay/solenoid have to be up to the task too.

In some designs the shutdown solenoid has a rubber valve seal that can deteriorate and bits & pieces can clog fuel system. It may appear that fuel is flowing but the volume may not be enough due to partial blockage. Might look into that if it still won't fire after cranking power is corrected.

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