Geoff Weeks Posted May 6 Share Posted May 6 "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. 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/ Share on other sites More sharing options...
Joseph Cummings Posted May 6 Share Posted May 6 What was it? Looks small Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575227 Share on other sites More sharing options...
Geoff Weeks Posted May 6 Author Share Posted May 6 D950 Kubota. Like most Kubota's when one cyl fails catastrophically it still runs on the other 2! No longer "wisper quiet" however! Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575231 Share on other sites More sharing options...
mowerman Posted May 6 Share Posted May 6 it doesnt even look repairable wow,,,,not a pretty sight,,bob Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575236 Share on other sites More sharing options...
Geoff Weeks Posted May 6 Author Share Posted May 6 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! 2 Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575248 Share on other sites More sharing options...
Geoff Weeks Posted May 8 Author Share Posted May 8 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. Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575359 Share on other sites More sharing options...
mowerman Posted May 8 Share Posted May 8 looks like you got lucky,,,good luck,,,rings look new,,bob Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575384 Share on other sites More sharing options...
Geoff Weeks Posted May 8 Author Share Posted May 8 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. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575391 Share on other sites More sharing options...
Joseph Cummings Posted May 9 Share Posted May 9 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? Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575393 Share on other sites More sharing options...
Geoff Weeks Posted May 9 Author Share Posted May 9 No, a 6kw light tower. 1800 rpm tho. Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575394 Share on other sites More sharing options...
Joseph Cummings Posted Sunday at 02:10 PM Share Posted Sunday at 02:10 PM 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. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575493 Share on other sites More sharing options...
Geoff Weeks Posted Sunday at 02:21 PM Author Share Posted Sunday at 02:21 PM (edited) Wacker LT-4? No, wait the cabinet is different. Edited Sunday at 02:22 PM by Geoff Weeks Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575494 Share on other sites More sharing options...
Geoff Weeks Posted Sunday at 03:07 PM Author Share Posted Sunday at 03:07 PM 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. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575497 Share on other sites More sharing options...
Joseph Cummings Posted Sunday at 04:35 PM Share Posted Sunday at 04:35 PM 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 Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575499 Share on other sites More sharing options...
Geoff Weeks Posted Sunday at 04:51 PM Author Share Posted Sunday at 04:51 PM (edited) 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 Sunday at 04:51 PM by Geoff Weeks Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575500 Share on other sites More sharing options...
Geoff Weeks Posted Sunday at 05:19 PM Author Share Posted Sunday at 05:19 PM 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! Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575501 Share on other sites More sharing options...
Joseph Cummings Posted Sunday at 05:41 PM Share Posted Sunday at 05:41 PM 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575502 Share on other sites More sharing options...
Jack Mack Posted Sunday at 09:36 PM Share Posted Sunday at 09:36 PM 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 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575509 Share on other sites More sharing options...
Geoff Weeks Posted Sunday at 10:00 PM Author Share Posted Sunday at 10:00 PM 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. Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575510 Share on other sites More sharing options...
Joseph Cummings Posted Sunday at 10:04 PM Share Posted Sunday at 10:04 PM 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 Quote Link to comment https://www.bigmacktrucks.com/topic/75495-not-a-truck-but/#findComment-575512 Share on other sites More sharing options...
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