12 volts between the positive terminal of battery and glow plugs at all times, bad?

[Soundguy]

and not if you do the comp test accurately with other injectors out too...

I agree.. 200's psi is dismal...

 

[crazyal]

Yes, if it had sufficient compression. Not likely with those numbers. If they were in the 400+ psi range there is a good chance it would, but only for a few revolutions, not a big deal.

Brian

I understand that with a low pressure the engine will not fire but if it is the rings and by adding some oil the compression could jump up and be high enough to fire. Would a compression tester handle that kind of pressure. I thought I read somewhere that it could be thousands of PSI. After wondering and doing a quick search it seams there are lots of warning not to do it, even a youtube showing an adapter getting blown out when the oil in the cylinder fired.

 

[brain55]

I understand that with a low pressure the engine will not fire but if it is the rings and by adding some oil the compression could jump up and be high enough to fire. Would a compression tester handle that kind of pressure. I thought I read somewhere that it could be thousands of PSI. After wondering and doing a quick search it seams there are lots of warning not to do it, even a youtube showing an adapter getting blown out when the oil in the cylinder fired.

I suppose that in the 25+ years I have doing it, I've just been lucky. Personally I don't think the risk is that great.

Brian

 

[crazyal]

I suppose that in the 25+ years I have doing it, I've just been lucky. Personally I don't think the risk is that great.

Brian

Thanks. You often see things saying don't do this but they don't say how much of a risk.

 

[Soundguy]

adding a bit of oil to a cyl to seal the rings lets you see if it is a ring or valve issue.

you can't add oil to all of them.. in fact.. i leave all of them open but the one i'm testing.

chances are on that claptrap.. oil will hardly bring it up enough to be inthe viable range...

 

[RickB]

adding a bit of oil to a cyl to seal the rings lets you see if it is a ring or valve issue.

you can't add oil to all of them.. in fact.. i leave all of them open but the one i'm testing.

chances are on that claptrap.. oil will hardly bring it up enough to be inthe viable range...

Agree. If it won't run on 3 cylinders dry, it sure as heck isn't going to light off & run on one cylinder with a little engine oil in it.

 

[SilverLakeFab]

B6100 failure update:

It's been a bit since I've posted, but I've made some good progress on fixing this problem. The engine has been removed, fully disassembled, professionally inspected, and bored 0.5 mm over (first over bore for available pistons). As suspected, the cylinders were out of round, with the worst (the 200 PSI cylinder) being off by 0.008". I just picked up the block today and all the parts I should need are on the way from Kubota. I sure have my fingers crossed that I've ordered everything I need since half the parts had to be ordered straight from Japan and I'm told they should take 4-8 weeks to get (ordered a week ago, so I'm still out a while before reassembly). Almost everything came apart easily and I only had two minor fatalities, as I had to cut off an exhaust manifold nut (on the stud that holds on the muffler) and I managed to break the water inlet plate/stator base plate that bolts to the head. Luckily, the stator plate was only $28 and I should be able to heat and remove the cut stud from the exhaust manifold with a trick I know of. I ended up ordering all the parts from Interstate Equipment, as they saved me about $300 on everything I needed over the local dealer and other dealers online, so props to them. I would also like to give props to Sanel's Machine shop in Concord, NH as well. They bored all three cylinders for $150, which for a 0.020" overbore is pretty reasonable. They usually have a couple week backlog, but that's to be expected.

Below are three pictures from the project so far. The picture in the middle was taken today after the block was picked up from the machine shop. I plan to thoroughly clean and repaint everythying before reassembly, including the motor and front frame. I'll also be swapping out the radiator for a modified aluminum unit (aftermarket unit for a Honda Civic) and adding a belt driven in-line water pump (a unit for a Mini Cooper S) to keep everything cool on this little beast. If all goes well, it'll all fit under the hood and you won't be able to see it. After that, I'll be mounting a Kubota LA302 FEL that I picked up last spring (mounting frame is 70% complete for that). I'll post pictures as I get to continue this project, but thanks to everyone who chimed in on my engine problem.

 

[SilverLakeFab]

After a 9 week wait, the pistons, rings, bearings, gaskets, seals, and coolant outlet/stator mount have all arrived and I've been able to start reassembly. Of everything in the kit, the only thing I was unable to install in my shop were the top connecting rod bearings, as they are very thin, and have to be pressed in and line bored. Once again, Sanel's machine shop in Concord, NH did a great job with this and had the parts back to me in 2 days with a $45 cost, which was well worth it.

So far, the block has been thoroughly cleaned, wire brushed, and primed. Also, the crankshaft has been installed, two of the three pistons installed (I somehow manage to strip one of the connecting rod bolts, so I'm out another week on installing the third piston assembly), and all the front gears have been reinstalled. All the other pieces have been thoroughly cleaned, stripped, and as of tonight, primed. Tonight's batch of cleaned and stipped parts will receive another coat of primer tomorrow, and as soon as the new connecting rod bolts arrive, everything will be bolted back together with primer on it.


I had a batch of single stage automotive paint mixed up to match the factory Kubota paint ($85 for everytyhing I needed for the job, including hardner and thinner - once again, yay Sanel Auto Parts!), so as soon as I have everything bolted on and torqued, I'll paint the engine assembly as a whole. The front of this little machine is going to look brand new (other than the hood), so I got enough paint to do the rest of the blue when I have time to strip that part down. Once the chassis is repainted, I plan to strip down, pop out any dents, and paint the hood, fenders, and dash panel.

So everyone can see where I am so far, I've attached pictures of what else has happened since my last post. Once I have the engine assembled, I'll post more pictures.

 

[SilverLakeFab]

I'm down to bolting on the fuel injection pump on this machine and there are 5 shims that go between it and the block. When I took them apart, they had some sort of liquid gasket between them. Does anyone know what to use for that? Neither the local Kubota dealer or any of the local automotive parts places know what to use there.

Thanks!

 

[SilverLakeFab]

I used a high-temp thread sealant and it works great!