643 bogs down

[Jasonb1072]

So I got this thing running. Its older I believe its an 85 and the meter says 6500 hours although I think its been rebuilt but I can't say for sure. But when its running full throttle and I'm using it if I push into some dirt it bogs down and I got to back up and go forward again. I stalled it once like this and it was loose dirt and not even a full bucket. The other thing is if I'm doing multiple functions like raising and tilting the bucket while moving it bogs down a lot. I didn't know if this was typical with the older machines because of the smaller motors of if this one is just old and doesn't have much power or what. This is my first bobcat so i don't have anything to base it off. This may not be anything that I can fix but I thought I would just ask. Thanks guys!

 

[OldMachinist]

How easy does it start? Does always need a good glow?
I'd check the engine compression and have the fuel injectors checked.
The other thing is to make sure the aux. hydraulics arn't stuck on or partially on.

 

[Jasonb1072]

How easy does it start? Does always need a good glow?
I'd check the engine compression and have the fuel injectors checked.
The other thing is to make sure the aux. hydraulics arn't stuck on or partially on.

Well its been between 60 and 70 degrees and the initial start up from cold is about 15 seconds and it turns over for about 2-4 seconds and then fires and speeds up to idle. The injectors are brand new and Ill have to check the compression on it. It should be around 350psi per cylinder right? I know the control for the Aux is the right drive stick left/right How do I know if its stuck? Does anyone know of replacement diesel motors for the 643 besides the D1402? Thanks!

 

[Tazza]

Well its been between 60 and 70 degrees and the initial start up from cold is about 15 seconds and it turns over for about 2-4 seconds and then fires and speeds up to idle. The injectors are brand new and Ill have to check the compression on it. It should be around 350psi per cylinder right? I know the control for the Aux is the right drive stick left/right How do I know if its stuck? Does anyone know of replacement diesel motors for the 643 besides the D1402? Thanks!

350PSI is the very low end for a diesel. You should have 450+ when new.
That sounds like a pretty good start, you may just be pushing it a little harder than the engine can handle? Push into it slower and see what it does. You should be able to get the tyres to spin, or at least one side at a time.