B6100 Engine rebuild impossible?

sfixx · Jul 31, 2007

I got a call from my local Kubota service manager this morning and now kind of feel like their has been a death in the family. I took the tractor in to have the low oil pressure light "on" problem diagnosed. The reply is that the pressure sending unit is okay and we cannot know more until we dig into the engine, however if there is much damage all the parts needed to fix it may not be available (including a remanufactured engine). I had already explained to the service manager that the previous owner drove the thing with the light on for quite some time which of course gives us cause for concern that the damage may be extensive(though it doesn't now smoke excessively). The PO has offered to fix the low oil pressure problem at his expense, but if we cannot fix the damage caused I'm wondering what's the point? I think that all the standard parts are available like bearings, seals, rings, and gaskets but pistons and some critical fuel system parts are not.

Got an Opinion on this? Has anybody run into a parts shortage with these motors? Are B6100's getting scrapped by the boat load? I thought that I had a great little tractor with outstanding parts support!

Thanks,

Steve

robbieo11 · Jul 31, 2007

if you have them speced it seem as thougha good machine shop in yourarea would be able to assist in getting parts

if not try a bearing speacialty shop

sfixx · Aug 1, 2007

robbieo11 said:
if you have them speced it seem as thougha good machine shop in yourarea would be able to assist in getting parts if not try a bearing speacialty shop

Yes, he said that custom machining may be the only option for some parts but then the repair costs increase dramatically

Thanks for your reply,

Steve

sfixx · Aug 5, 2007

The previous owner has agreed to pay the bill to replace the oil pump. $188 for parts and $450 for labor. It's a bit of a gamble but the shop is quoting 8 hours just to get into the crankcase to inspect and measure further damage. And since it's not smoking excessively, makes good power, doesn't burn oil or have oil in the water maybe we'll get lucky?

Does anybody have experience with low engine oil pressure related to any parts but a bad oil pump?

Thanks,

Steve

TalonDancer · Aug 5, 2007

sfixx said:
...Does anybody have experience with low engine oil pressure related to any parts but a bad oil pump?...

In all engines....
Excessive smoking & burning oil--> bad rings or valve guides/seals.
Oil in the water --> bad head gasket, cracked head or engine block
These are the least of your worries in a engine run with low oil pressure.

I would not even consider just replacing the oil pump. Oil pressure is what keeps the _revolving_ parts from EVER touching (e.g. rod bearings, cam bearings, etc.) . It takes less than a minute of running with no (or very low) oil pressure to severely damage the "bottom end" of any engine. Without oil pressure, the rod bearings contact the crankshaft and begin wearing out the soft rod bearings immediately. If you are extremely lucky, the wear is confined to the bearings themselves. If not, the crankshaft will be scored and possibly out of round or undersized. This is not a "remove and replace" sort of job. Even in the simplest bottom end rebuild, you have to mic the crank and dial gauge the rods and engine block to see if there are bearings avaialble to fit these worn parts. You may also have to turn and polish the crank.

Talon Dancer

robbieo11 · Aug 5, 2007

like the man said it could be the clearance on the bearings could be to far out causing the low presure. The smoke is exessve oil getting into firing chamber ie: worn valves guides or sealsthis also could be a sign of a worn or broken ring. You just do not know until it is torn down. The previous owner has committed to oil pump he therefore is assuming he is responseable. I would have him take care of the hole thing. if he will not have him eighter buy the unit backor take him to court for the repair costs