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Engine problems - not sure where to even start

Ncjetskier

Well-Known Member
Joined
Feb 7, 2022
Messages
126
Location
North Carolina
Serial number YQU4681

Yesterday, the machine started running rough and the rpms started to drop down. White smoke started coming out of the exhaust. All fluid levels were good. I shut the machine off, and started it back up and it straightened out and ran good for 3 hours.

Then it occurred again. The white smoke turned to dark black. Now oil is leaking out of the engine near the fuel injector pump.

The strange thing, is that the water temp went down (not up) both times this occurred.

Can someone give me an idea where to start looking at the engine to figure out what is going on? Thanks!!
 

Ncjetskier

Well-Known Member
Joined
Feb 7, 2022
Messages
126
Location
North Carolina
UPDATE: The bottom back plate of the injector pump was loose and was leaking oil (see below - the part held on with four black screws).

I replaced all filters (air and fuel). The motor will run good for about 10 minutes then will start losing RPMs and power, then it will return to normal RPMs. This happens again and again - non of the linkages move on the injector pump.

Here are my questions;

1) does the oil in the injector pump come from the engine, or do I need to refill what came out?
2) Using the serial number at the beginning of the post, can someone tell me the part number for the injector pump and what it is (I believe it is a Bosch pump)?
3) Can the injector pump be rebuilt, and if so - how?
4) any ideas of what would make the engine RPMs go up and down?
 

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  • Kobelco Injector Pump.jpg
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thepumpguysc

Senior Member
Joined
Mar 18, 2010
Messages
8,533
Location
Sunny South Carolina
Occupation
Master Inj.Pump rebuilder
I’m guessing it’s a Bosch “A” pump w an RSV gov..
A side shot of the pump will confirm..
There is also a name plate on the side just below where the lines screw on..
Yes they can b rebuilt..
I would replace the supply pump 1st.
 
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