Hi, I recently purchased a 1978 B6100d gear drive with 1700 hours showing on the meter. I knew it smoked out the breather when I purchased it, but otherwise ran OK. But I didn't know the oil pressure light was not working. Checked pressure and it was 6 lbs. Took to my mechanic and found cam plug in pan. Must have been run like this for a while as bearing were wore, Mechanic replaced crank and rod bearings, honed cylinders and replaced rings. He checked head for cracks and replaced valves (said rings weren't to bad but valves were). He called me to his shop today and reports it is difficult to start and blows white smoke while running. This tells him it's either low compression, bad pump or injectors. He will check compression as soon as he gets a chance, but is certain its not low. He is having a difficult time finding the degrees BTDC for pump timing. I've searched and have found anywhere from 17 to 25 BTDC. I've phone the diesel mechanics in my area and they claim they are not set up to check injectors and simply replace them. My mechanic has not added up his cost in parts yet, but did say he was shocked at how expensive Kubota parts are. I don't want to keep pumping money into the beast. If compression and the pump are within normal range would it work to buy an injector cleaner and try letting it clean itself? Any other suggestions? I'm a little concerned because it didn't blow this much white smoke before the rebuild. Thanks
New to me b6100-now engine problems!
- Thread starter BobN
- Start date
Wow, thanks Vic! That information may help! The fuel is clean, new fuel filter and air cleaner. I hope it's not the compression, unless maybe the valves only need adjusting. My guess at this point is the injectors may need replaced. Unfortunately I'm unable to find someone willing to test them, unless I take a day and drive to the big city. I tried searching for prices on injectors for the D650 engine, but no luck. If not too expensive I would order 3 and see if it fixes the problem. I do need to order a service manual, a PDF would be nice. Aware of a place to download one?
Thanks for all suggestions
Thanks for all suggestions
http://www.dfispdx.com/
I rebuilt a L295DT last year.....the primary reason being the oil was pressurizing the crank case, and I didn't know why. Well, figured that out, but during the "adventure", I also found the injectors were needing some attention.
Diesel Fuel Injection Service in Portland was awesome.
$135 to rebuild all three - shipping included!.
Highly recomended.
Dave
I rebuilt a L295DT last year.....the primary reason being the oil was pressurizing the crank case, and I didn't know why. Well, figured that out, but during the "adventure", I also found the injectors were needing some attention.
Diesel Fuel Injection Service in Portland was awesome.
$135 to rebuild all three - shipping included!.
Highly recomended.
Dave
Thanks for the suggestions! My mechanic had to cobble together a bunch of fittings in an attempt to get a compression reading. The readings on each cylinder were above 400, but he felt not accurate do to his set up. He ordered the correct fittings and will arrive today. I found a diesel shop 30 minutes away that claim they can test and possibly order parts and rebuild my injectors if needed. I unfortunately work 12 hours shifts the next several days, so maybe Friday I'll have more answers. FJ40DAve that price sounds good, I was able to find one place online that had rebuillt injectors at $75 a piece plus a $20 core charge, your price sounds more reasonable.
Vic, the mechanic confirmed the valves were properly adjusted and the compression relief valve has been checked and working fine. The more I read the more is seems possible my problem is injectors.
Thanks again!
Vic, the mechanic confirmed the valves were properly adjusted and the compression relief valve has been checked and working fine. The more I read the more is seems possible my problem is injectors.
Thanks again!
Not what I wanted to hear!! Compression is low on all 3 cylinders. Mechanic confident valves are fine, he did hone the cylinders, but feels he took very little off and pistons fit well. At this point it looks like my options are to have engine tore apart and next larger pistons installed, or push it into the corner of the shed and forget about it for a couple of years. I'm going to have him add up the bill to this point and then make my decision. Ill have him double check the compression relief, but I believe my options are limited.
Thanks
Thanks
You're welcome for the lead on the injector rebuild (DFIS in Portland, OR)
They really are great to deal with.
BobN.....stay with the momentum....put that B6100 together and anjoy it.....often, I had to force myself to go back out to the garage - but in the end, I really enjoyed running the thing knowing I built it (and I never even drove a Kubota before that one!).
Of course, if you just can't see it happening, you can ship it to me
They really are great to deal with.
BobN.....stay with the momentum....put that B6100 together and anjoy it.....often, I had to force myself to go back out to the garage - but in the end, I really enjoyed running the thing knowing I built it (and I never even drove a Kubota before that one!).
Of course, if you just can't see it happening, you can ship it to me
Kubota Newbie
Active member
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M4500, New Idea Cut-Ditioner, JD 14T Baler, IH "Plow Chief" plows, Oliver Rake
I don't get it!
If this thing "ran ok" but just "smoked a little from the breather", meaning that it started ok and didn't blow white smoke from the exhaust before this mechanic got ahold of it. But now... it will barely start and blows white smoke continuously when it does run after new rings, valves and bearings?
I think I'd be having a pretty stern discussion with my "mechanic". He's missed something during re-assembly. None of those things, if done properly, should have worsened the running condition of the motor.
If this thing "ran ok" but just "smoked a little from the breather", meaning that it started ok and didn't blow white smoke from the exhaust before this mechanic got ahold of it. But now... it will barely start and blows white smoke continuously when it does run after new rings, valves and bearings?
I think I'd be having a pretty stern discussion with my "mechanic". He's missed something during re-assembly. None of those things, if done properly, should have worsened the running condition of the motor.
It is not good practice to "rering" a diesel engine unless it has very few hr's on it. Any taper or out of roundness in the cylinders will prevent the new rings from sealing well and lead to a poor starting engine. This is especially true in small diesels. It MIGHT wear in given time but it likely will be more time than you're willing to give it. I often resleeve them and reuse the old pistons though. Kubota only supply "rough" sleeves so the engine must be disassembled to bore the new sleeves to size. You should disassemble it if you're boring it to fit oversize pistons anyway so it becomes an issue of whether oversized pistons or new fitted sleeves are cheaper.
I agree that if it ran ok before it was torn down something was done wrong. It was said the valve were replaced, but were the seats ground? Since mains were put in it, that means the crank was removed. Did it get timed correctly? I woudln't start blaming the pump and injectors. I would blame the "so called" mechanic.
I have a B6100E that has so much blowby you have to hold your breath at times if the wind isn't blowing. The exhaust is fine. I have a 4', 3 pt. finish mower that I have used like a shredder, mowing down 1' tall grass and weeds. The old thing does fine and doesn't over heat.
Kubota Newbie
Active member
Equipment
M4500, New Idea Cut-Ditioner, JD 14T Baler, IH "Plow Chief" plows, Oliver Rake
Ditto what eserv and SD Vic said.
Except that... I wouldn't waste my time and money just "re-ringing" ANYTHING unless I was just planning on unloading it real soon. If it's going to come apart, bore and hone to an oversize piston or sleeve and re-bore to standard.
Your mechanic "feels" he didn't take very much off when he honed the cyls. Does that mean he didn't bother to measure before and after cyl size and/or compare that to the worn piston diameter. He should know exactly how many thousandths he took out. Did he check the ring end gap? Did he re-grind the new valves AND seats before installation? Did he vacuum test the valve job before he assembled the valve springs and retainers (or at least lap them in)? The list of possibilities just goes on and on.
I still think you need to ask some hard questions to this guy. If he can't give you the correct answers to questions like these and the ones SD Vic had he should be paying you! At the very least he should make it right at no cost.
You might also try pressure testing the cyls - pressurize each cly to about 30-40 psi with the radiator cap off and the dipstick out, valves closed for that cyl. Listen to see where the biggest leak is coming from. Should hear nothing from the intake or exhaust and only a very slow hiss from the crank case vent. Also check for bubbles in the radiator. You don't see them much any more but a lot of shops used to have engine analyzer set-ups that would measure the % cyl leakage during the cyl pressure test and give you an idea if it was within reason.
Except that... I wouldn't waste my time and money just "re-ringing" ANYTHING unless I was just planning on unloading it real soon. If it's going to come apart, bore and hone to an oversize piston or sleeve and re-bore to standard.
Your mechanic "feels" he didn't take very much off when he honed the cyls. Does that mean he didn't bother to measure before and after cyl size and/or compare that to the worn piston diameter. He should know exactly how many thousandths he took out. Did he check the ring end gap? Did he re-grind the new valves AND seats before installation? Did he vacuum test the valve job before he assembled the valve springs and retainers (or at least lap them in)? The list of possibilities just goes on and on.
I still think you need to ask some hard questions to this guy. If he can't give you the correct answers to questions like these and the ones SD Vic had he should be paying you! At the very least he should make it right at no cost.
You might also try pressure testing the cyls - pressurize each cly to about 30-40 psi with the radiator cap off and the dipstick out, valves closed for that cyl. Listen to see where the biggest leak is coming from. Should hear nothing from the intake or exhaust and only a very slow hiss from the crank case vent. Also check for bubbles in the radiator. You don't see them much any more but a lot of shops used to have engine analyzer set-ups that would measure the % cyl leakage during the cyl pressure test and give you an idea if it was within reason.
Thank you for all the responses! I've had to work all day today and will be out of town all weekend, but Monday or Tuesday I'll get some answers to many of your questions. I believe the biggest mistake the mechanic made was not having a service manual for the engine to work with. I requested a PDF version from a website 2 days ago, but have not recieved it yet, I may have to order a paper version. If anyone could possible give me the specs for the cylinders I'd appreciate it! The compression on the cylinders was 290-330 on the various pistons, so pretty low. I took the injectors to be tested and my voice mail had a message today that all 3 tested bad, so this may explain a little of the hard starting and smoking. The mechanic suggested taking it home and putting a couple of hours on it and than rechecking the compression. I don't think either one of us believes it will make a difference, but I'll try it. One of you guys mentioned "rough" cylinder liners, the mechanic thought liners would be the way to go, as opposed to boring and new pistons. I still don't know how much more money I'm willing to put into this thing, but will know more next week.
Thanks again
Thanks again
I picked up the injectors today after having them rebuilt, the price for all 3 was $130. The mechanic did a leak down test and it confirmed the compression is leaking past the rings. He priced new cylinder liners at $103 a piece, so that's $300.00 more I'm going to put into the tractor, not counting new gaskets! He is going to work with me on his labor charges as he knows he's ultimately responsible to make it run correctly, but still just the price for parts is going to be very high! I imagine it will be at least a week or 2 before he is able to work on it, I'll update when I know more.
Thanks
Thanks
Dave what led you to believe your injectors needed some attention? I live close to Portland Or, have a 1974 B7000 and have thought about servicing the injectors!
But how do I know if they need attention?
But how do I know if they need attention?
When you install those sleeves they will need to be bored to the proper size. this means complete diassembly of the engine and a trip to the machine shop! better figure at least another 500 dollars above the cost of sleeves.
Ed
Ed
I'm back!! Thought I would give an update on the engine repair. On my last post I was contemplating what to do, as I had a bunch of money already invested in the engine and I had just learned my only option was to have it sleeved. I paid $1500 for the tractor and I knew when I purchased it, would at least need new rings, but soon found out it had been run without decent oil pressure for some time. My mechanic at that time gave me an estimate of $1000 for the work(he had no idea the cost of Kubota parts). Well since then I had the engine sent to a local machine shop to install, bore and fit sleeves, install new pistons and rings, deck block(.013"), resurface head, new valves and valve guides, reface seats, remove and machine prechamber counterbore, mill piston tops, recondition rods and install new bushings. The engine has all new bearings, gaskets, rebuillt injectors and what ever else was needed. I finally got the tractor back 2 days ago!! It runs much better than the day I bought it, starts great has a noticable increase in power and absolutely no blowby. I've only had the chance to run it for about 2 hours, but unlike before the rebuild the engine oil stays clean. I do have a couple of concerns. When the tractor is ran without a load the exhaust is clear. If I run the belly mower deck I have a small amout of white smoke and when I hit deeper grass it will blow a good amount of black smoke. I realize some of this is considered normal, but how much? The mechanic removed one of the shims on the injector box during the rebuild as he felt the timing was off, but other than injector timing everything else has been replaced. Thanks for all the help.