Kubota M5700 low compression after rebuild

Chays

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Oct 28, 2019
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Brandon,ms
Just did complete rebuild on my 5 cylinder f2803 new sleeves ,pistons,
Complete valve job on head,cranks and runs but not good and
Only has 175lbs compression.my mechanic says I should be around
500 lbs compression give or take.he has taken injection pump and injectors
And had them check all good.trator only has 530 hours on it.
This is the indirect injection engine also.

Any suggestions would be great at this points?
 

200mph

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Did all 5 cylinders read 175 psi? Please list the individual readings.

Have you considered a leakdown test to verify where the leak is coming from - rings, valves, etc?


With only 530 hours why was a complete rebuild needed?
 

North Idaho Wolfman

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How is it for blow by?

Was a kubota head gasket used or aftermarket one?

Was any milling work done to the head or the block?

Does it run at all?

And yes exact numbers on which cylinders would be very helpful.
 

Chays

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Oct 28, 2019
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Brandon,ms
Did all 5 cylinders read 175 psi? Please list the individual readings.

Have you considered a leakdown test to verify where the leak is coming

from - rings, valves, etc?would have to guy working on it


With only 530 hours why was a complete rebuild needed?
Had crazy blow by.number5 cylinder rings were gone block was worn bad.
Motor has never had a drop of dirt in it and change oil and all filters ever 100 hours nit sure what happen.
 

200mph

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Had crazy blow by.number5 cylinder rings were gone block was worn bad.
Motor has never had a drop of dirt in it and change oil and all filters ever 100 hours nit sure what happen.
It sounds like these are the results of the original motor.

Curious if you did a leakdown test on the rebuild (with low compression) and what the results were.

What are the compression readings for each cylinder?
 

North Idaho Wolfman

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Had crazy blow by.number5 cylinder rings were gone block was worn bad.
Motor has never had a drop of dirt in it and change oil and all filters ever 100 hours nit sure what happen.
Yea I mean blow by after the rebuild... and does it even start now?
 

Russell King

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... on head,cranks and runs but not good and...Only has 175lbs compression.
In the original post he said it would crank and run, but with only 175 psi compression I am not sure that is possible if all cylinders are that low...

What do the experts think about it running with all cylinders at 175 psi?


Sent from my iPad using Tapatalk
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
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Sandpoint, ID
In the original post he said it would crank and run, but with only 175 psi compression I am not sure that is possible if all cylinders are that low...

What do the experts think about it running with all cylinders at 175 psi?


Sent from my iPad using Tapatalk
Yea that's why I wanted some clarity, as it shouldn't start or run if it only has 175 PSI!