Not a truck, but

[Geoff Weeks]

"Has fuel system problem, starts and runs on ether'!

Yeah it will have a fuel system problem if you don't run a fuel filter on a diesel.

And NO it doesn't run on ether, for long.

[Joseph Cummings]

What was it? Looks small

[Geoff Weeks]

D950 Kubota. Like most Kubota's when one cyl fails catastrophically it still runs on the other 2! No longer "wisper quiet" however!

[mowerman]

it doesnt even look repairable wow,,,,not a pretty sight,,bob

[Geoff Weeks]

Depends on how bad the bores are, It is dry lined engine so as long as any damage hasn't penetrated the liner into the block, it should be rebuild able. 

I've got some used pistons that don't look bad, and it will need at least one rod. Rod could be removed from the bottom with the head in place!

The effected rod big end looks fine, both crank and bearing shells.

Unit came with a top end gasket kit, another new set of main bearings, and assorted loose gaskets.

Had it running long enough to verify the generator it was attached to works, so I know it is worth putting a little into it.

Kubota's are tough little engines!

[Geoff Weeks]

Got tore down this AM,  block, head, crank are all good, needs one liner, one rod. Going with a good set of used pistons I have.

These engines use a shim between the head gasket and head if the piston clearance isn't to spec (block or head have been decked) it looks like he needed one and didn't install one.

[mowerman]

looks like you got lucky,,,good luck,,,rings look new,,bob

[Geoff Weeks]

I doubt the rings have 1 hr of run time on them.

When ever you buy at auction is is a roll of the dice.

I knew this didn't run when purchased  and paid less then scrap, I can put a little into it and be fine.

I need to buy some tooling to work on an engine this small, need a smaller "rack" for my index hone and a 75mm ring compressor.

fortunately, the seller provided the old parts he took out, and they didn't have many hr on them either.

According to the writing on the air cleaner, it has a grand total of 32 hr run time since 2013.

Engine has a rebuild tag from some outfit I haven't heard of. My guess is both the block deck and head have been shaved, raising the compression and bringing the piston too close to the head.

It likely ran ok when the engine came from the rebuilder, but when it got worked, the clearances were too tight and the pressures too high, which lead to one rod failure. The guy I got it from tried to rebuild and made it worse.

piston to head clearance spec is 0.024-0.031". go to much it it will have low compression, with all that brings, go too little and you end up where I am at.

I will try and end up in the higher end of that spec, but it all depends on what thickness gaskets are when compressed and what cylinder head shim I can lay my hands on.

I'll start by measuring the piston protrusion or lack there of, in relation to the block deck, then mic the old head gasket thickness to get a ball park figure, then add in a shim if needed, and finely assemble with a piece of solder through the injector port and roll passed TDC to get the final assembly clearance. If it is not correct, then a new head gasket and more or different shim.

I don't know of too many engines that can survive a running failure of a piston and not take out the block. Kubota's are tough little engines.

[Joseph Cummings]

On 5/6/2025 at 4:29 PM, Geoff Weeks said:

Had it running long enough to verify the generator it was attached to works, so I know it is worth putting a little into it.

About a 10 KW 1800 RPM gen-set?

[Geoff Weeks]

No, a 6kw light tower. 1800 rpm tho.

[Joseph Cummings]

On 5/8/2025 at 10:18 PM, Geoff Weeks said:

No, a 6kw light tower. 1800 rpm tho.

 

On 5/8/2025 at 10:18 PM, Geoff Weeks said:

No, a 6kw light tower. 1800 rpm tho.

I think those are about 14ish HP at 1800, so they probably oversized the engine a bit. Those things can rack up lots of hours so they probably sized t to not be working so hard.

I have the same one on a light tower. I have one bad bulb, I was just going to buy 4 LEDs for it. Probably won't be working anywhere near hard then.

[Geoff Weeks]

Wacker LT-4?

No, wait the cabinet is different.

Edited May 11 by Geoff Weeks

[Geoff Weeks]

Thanks for the picture, BTW, Mine had been messed with and the air cleaner and overflow bottle were moved and poorly mounted. I can easily see how they are supposed to go on.

[Joseph Cummings]

This one say "Boss" on the manufacturers tag. I'll turn the garage lights on and get a better picture of the air cleaner. It puts out a lot of light, I would think I could add more lights if I switch to LEDs

[Geoff Weeks]

I don't need a better picture, but thanks.

On mine he had flipped the aircleaner around and bolted it with one bolt to the bellhousing where the timing hole cover was. I can see it bolts in front of and below the I/P where there are two hole that just happen to match the bracket for the air cleaner, imagine that?

It seams like anyone and everyone with a small shop was producing these back then. Now the big players bought out the little guys and there are only a few producers still in the game.

Edited May 11 by Geoff Weeks

[Geoff Weeks]

You know you're dealing with a rebuilder who is really proud of his work, when he grinds the OEM stamping of the engine number off and this is the only ID on the engine!

[Joseph Cummings]

[Jack Mack]

The construction company I work for when light towers get old and have issues the Electrical Team gets them to convert into job site trailer generators, to run them out instead of having a failure on the roadway. I have 69 generators  from 6KW to 100KW, 16 are light tower conversions and most are Kubotas and a lot are over 40,000 hours, the other brand engines don't last as long and require more work to get there, looks like you got lucky.....Jack 

[Geoff Weeks]

I went and took my "liner protrusion" gauge I have for checking liner height on Cummins rebuilds, to check the two remaining pistons, one is a few tho proud and the other a few tho under the deck? Hum  could this have something to do with it? Another fractured piston pin!

The replacement pin fitted piston he used have a thinner wall pin then the OEM IZUNI pistons he took out. Weighed them on a scale, 75g vs 100 g.

I can't remember ever seeing two (or even one) fractured piston pins on an engine, let alone one that would still run!

Knocked the old bushing out of the rod with the fractured pin and installed a new bushing, Easiest way to check and see if it is good, Bushing was a snug fit and was honed to size for the OEM pin.

I saw that he also put a big divot in the upper rod bearing shell, looks like he hammered the rod out with a long screwdriver on the shell! So a new set for that rod as well.

So all in all it is looking like:

one set of rod bearing shells

one liner

one used rod

That is it for purchased parts.

re-fit the IZUNI pistons and pins, put the best set of rings on them, and put together, double check the head gasket I have to make sure it doesn't protrude inside the liner, and double check piston to head clearance.

[Joseph Cummings]

19 minutes ago, Jack Mack said:

The construction company I work for when light towers get old and have issues the Electrical Team gets them to convert into job site trailer generators, to run them out instead of having a failure on the roadway. I have 69 generators  from 6KW to 100KW, 16 are light tower conversions and most are Kubotas and a lot are over 40,000 hours, the other brand engines don't last as long and require more work to get there, looks like you got lucky.....Jack 

My buddy ran his whole place on a Lister powered light tower generator. Shop equipment too, even a big Monarch lathe and a Bridgeport running on a rotary phase converter. It was only a little 2 cylinder with a 6KW on it. The inertia from the phase converter helped with the motor starts, but the lights still dimmed a bit and the frequency dropped down to like 50 for a few seconds. That little Lister was working, but she took it. As far as I know it still runs. He just used it until he got a PP&L connection

[Geoff Weeks]

Its been a coupla months now. I can't get the correct liners to fit this block, too big around, too tall but listed for this engine.

I found a N.O.S. block with liners already installed, 1st arrive cracked, dropped at the factory! Inside a factory sealed box, no damage to the double wall box, but the casting was deformed and cracked. 2nd one arrived in good shape.

 This is one of those things where you can see the obvious failure, but not the "hidden" failures that lead up to it.

The engine failed due to improper assembly, the gasket protruded into the bore, and the piston hit the gasket and shattered. 

What wasn't obvious until complete tear-down, was he didn't replace the front crank bushing when he installed a -.2mm reground crank, and he didn't remove the timing gear off the crank and forced it though the bushing damaging it. He also "lost" a couple of springs in the gov assemble and tried to shorten the remaining one!

 So even if could have got the liner in, I would still have had an engine with major problems, low oil pressure and a governor that wouldn't hold the engine speed correctly or might even overspeed.

All the "hidden" problems showed when I stripped the original block and started building the replacement.

 I'll end up with a unit that cost me about what I could have paid for a running unit from a rental house, but I'll have essentially a "new" engine that should outlast me. A cautionary tale about buying un proved things at auction.

[tjc transport]

we had the same damaged block issue 4 years ago with a brand new Yanmar 3 cylinder diesel long block. 

shipper tried to say we dropped it, but in large letters on delivery receipt was shipping crate damaged, looks like it was dropped. 

it still took them three months to ship out another because they swore we dropped it. 

luckily it was during winter when the roller went down, so we did not have to rent one to replace it.