Slow starter while battery is good

[Guto]

Hi,
I would apreciate your thoughts on this problem:
I have one of those chinese mini excavators (HT10 with Koop KD192f diesel motor). I recently couldn't get it to start while motor was warm, the starter seems to turn too slow. What we checked/tried so far:
1-the battery is ok (12,70 volts) ,also tried starting with jumpcables.
2-Diesel is inside fueltank and motor(we see some fumes coming out the exaust while trying to start)
3-We tried to start with starter fluid, no luck
4-There is no air in the fuel pipes (loosend the nut, fuel was seeping out)
5-Air filter and oil is clean
6-Throttlecable(?) seems right
7-I see one fuse which looks good
...
The machine has only worked for 9 hours (!)
I will remove back and side pannels to have a better look at everything...

Do you have an idea what the cause could be please?

 

[ahart]

I would probably start by load testing the battery, if the Chinese build batteries like they build other things, 9 hrs could be the lifespan. If the battery is good, I’d see how much current the starter is drawing. Obvious things like cable connections should also be checked.

 

[funwithfuel]

I'd check all grounds and measure voltage drops from battery out to starter.

 

[8V71]

Can you bar the engine over easily (with out excessive force)

 

[cfherrman]

Hook the boosters directly to the starter, might have a loose connection or broken wire