Well, I finally got time to get back out to the shop and check the deck. I can not see or feel any lip or ridge at all. Everything seems to be flat. I am a bit worried about whether the head gasket will seal in the area around that bit of missing material in the cylinder wall. Although, I have had the tractor for 5 years, and this is the first time I've had an issue with it. If it lasts another 5 years, I'll be doing good. Time will tell, I guess. I'm waiting for the head to get here on Thursday, so once it's installed, I'll post an update.
Cylinder wall and head "erosion"?
- Thread starter speedy5966
- Start date
Will think good thoughts about the deck surface for you. Picture was probably deceiving in seeing a raised surface. Agree about your concern of missing cylinder material in that area. It will be the weak link even with perfect deck to head surface mating.
Keep us posted
Keep us posted
Lay the head gasket onto the deck. Make sure the fire ring, the folded over band the circles each cylinder, is completely supported by metal. The erosion can exist just can't be under the fire ring. Do not be tempted to alter the fire ring there is more going on there than just a wrap. You have some movement over the dowel pins to shift the gasket.
Let us know (with pictures) the results. Jeff
Let us know (with pictures) the results. Jeff
Well, I ran a straight edge over it, and I didn't see any high or low spots, and it felt smooth to the touch. Jeff, I didn't see your post until after I got it back together, but I do know that a very small part of that erosion is under the gasket, but I don't know how much. I installed the new head, and got it back together this morning. There's good news and bad news. The good is, that it no longer pushes out coolant, nor does it overheat. Yay! Bad news is, now it's really hard to start, and when it does, it blows a TON of grayish black, sooty looking smoke. After it runs a while, it slowly changes to bluish smoke, which slowly goes away until it looks pretty normal, a touch of smoke when running, then more when its pulling. It seems to run and sound pretty normal. I haven't pulled it hard for any period of time, or put it to work yet, but it seems to have more power than before. But that may just be wishful thinking. After warming up, if you leave it set for even a minute or two, then restart it, it starts pretty easily, but blows the grayish sooty smoke for a bit, then fades to blueish, then fades out again. I thought maybe I got some dirt in the injectors, so I took them out and cleaned them. The one from the front cylinder (not the center one) was covered in black soot, which was not the case before I started it. I noticed when I was cleaning them, that the one with the soot on it, also had some buildup on the spacer, inside the injector. After cleaning them all, I put it back together, with no change. I checked the valves, to be sure that I had adjusted them correctly, and they were all .008 inches cold, just like the manual says. I thought maybe the compression release was too tight, so just to eliminate it, I ran it without the valve cover on it at all, but it wasn't any better.(didn't really make TOO big of a mess) I had it at idle, and loosened the lines on top of each injector, one at a time. The center cylinder didn't seem to slow the engine as much as the other two, but I chalked that up to the small difference in the chamber volume, with that cylinder the way it is. The weird thing is, it ran great before I tore it down, so I figure it must be something I did, but I don't know what. I followed the manual all the way, although it's pretty vague. I'm great with gasoline engines, but I'm really new to diesels. I'm thinking that, although I don't see or feel any blow-by, maybe a compression test is in order?
Anybody want a B7100, cheap? JK!
Thanks for everybody's help, I'd be lost without ya!
Anybody want a B7100, cheap?
JK!Thanks for everybody's help, I'd be lost without ya!
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North Idaho Wolfman
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Never had the injector pump out, nor ever adjusted it. I thought about the injectors, too, but why did it run fine before?
I have never tried it, but I have heard you can turn the injector lines around
so they face away from the engine and then install all three injectors onto them. Supposedly you can then crank the engine over and visually see if they are popping cleanly and atomizing the fuel well.
I am not sure how difficult it would be to bleed the air out of the lines without having the injectors firmly mounted though.
Just an update on mine. Wasn't able to get the engine started due to low compression. Mine had been overheating for the previous owner and then sat for 9 years before I got it it. Turns out I had missed some small cracks in the cylinder head in the webs between the valve seats.
The worst one was the cylinder that had all the erosion. Most likely coolant leaked in causing it, so likely yours was cracked as well. Good call on replacing it. Have one of the Kumar Bros replacements on order now as well!
Edit: This forum scales the photos too much to see the detail of the crack. You can see better quality photos of it on the progress thread on my blog if interested.
https://www.modernsurvivalists.com/discussion/topic/restoring-an-old-kubota-b20-compact-utility-tractor-and-putting-it-back-to-work/
The worst one was the cylinder that had all the erosion. Most likely coolant leaked in causing it, so likely yours was cracked as well. Good call on replacing it. Have one of the Kumar Bros replacements on order now as well!
Edit: This forum scales the photos too much to see the detail of the crack. You can see better quality photos of it on the progress thread on my blog if interested.
https://www.modernsurvivalists.com/discussion/topic/restoring-an-old-kubota-b20-compact-utility-tractor-and-putting-it-back-to-work/
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Ya, that's where I got my head from, as well. It looks pretty good, but I did notice that some of the coolant passage openings are noticeably smaller than the stock head. Sorry to hear the head was cracked, but at least you figured out your issue, and will soon be back on the road.
Funny you mention the injector test, that's exactly what I did. Wasn't too hard, just had to take the top part of the side panel loose, as well as the air cleaner, to move the side panel out of hte way enough to make room for the injectors. Everything looked good, and the atomization seemed good, too. But then again, I'm not a diesel guy; it could look bad, and I may not even know it. I put it back together, and moved the suspected bad injector from the front cylinder, to the back one. No change in how it runs, and I haven't had a chance to take it back apart, and see whether the sooty buildup moved with the injector, or stayed with the cylinder.
One thing I did notice, is that the one that had the sooty buildup on it, was the only one that had one thick shim on the spring inside the injector. The others had two thinner ones. Could the PO have adjusted that injector to make up for the lower compression, and now that the compression is back to normal, the tuning is off? Again, I'm not a diesel guy, so I don't know if that would make sense. I didn't think to number the injectors as I removed them from the cylinders, I wish now I would have.
Thanks for all the help guys, I really do appreciate it!
Funny you mention the injector test, that's exactly what I did. Wasn't too hard, just had to take the top part of the side panel loose, as well as the air cleaner, to move the side panel out of hte way enough to make room for the injectors. Everything looked good, and the atomization seemed good, too. But then again, I'm not a diesel guy; it could look bad, and I may not even know it. I put it back together, and moved the suspected bad injector from the front cylinder, to the back one. No change in how it runs, and I haven't had a chance to take it back apart, and see whether the sooty buildup moved with the injector, or stayed with the cylinder.
One thing I did notice, is that the one that had the sooty buildup on it, was the only one that had one thick shim on the spring inside the injector. The others had two thinner ones. Could the PO have adjusted that injector to make up for the lower compression, and now that the compression is back to normal, the tuning is off? Again, I'm not a diesel guy, so I don't know if that would make sense. I didn't think to number the injectors as I removed them from the cylinders, I wish now I would have.
Thanks for all the help guys, I really do appreciate it!
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North Idaho Wolfman
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You sound pretty confident in that, and I'm sure you know a ton more than me. I just like to be sure of something before I commit to spending money. My "financial advisor" is already complaining about the $500-ish for the head and gasket set, and still no usable tractor. Thinking to get a whole new set, and keep the two seemingly good ones I have now, as spares. There are a few sellers on flea-bay that have them for less than $50 a piece. I'm just puzzled as to why it ran so good before. That's the only thing that has prevented me from getting new ones already. Guess I'll get them on order, and pray that it fixes it.Sounds like you have bad injectors... Oh yea already said that.
Thanks!
If you can find a diesel/turbo shop in a favorable distance they can check your injectors spray pattern and pop off pressure, then you know which direction to go. The shop I use has never charged me for that service. I'd say call for time required, and cost before you go.
D2Cat, ya, I had called a tractor shop and a diesel shop nearby, neither could test them. Closest place, according to them, was about an hour away. Not too far, but I decided to just replace them anyway. Just got it all back together, but still no change. In fact, now it has picked up a nasty sounding rattling noise for about 20-30 seconds, beginning about 20-30 seconds after it starts. Not sure if that's relevant. So then, I finally decided to buy a diesel compression tester at the local cheap-o-tools place, and ran a test. 210 in the front and center, 250 in the rear one. I'm no diesel expert by any means, but I figure that could account for at least some of why it's not running the greatest, especially when cold. I haven't done the wet vs dry test with oil yet, but I,m pretty sure I know what it's gonna tell me. My other question still remains, however: Why did it run so good before? What, if anything, did I do wrong?
Theory: Again, I'm no diesel expert, so if this is way off, please let me know. Could the injector pump be malfunctioning in some way, where it is pumping the wrong amount of fuel to some of the cylinders? My thinking is that maybe the PO adjusted the shims in the injectors, to compensate for the pump. Then when I took it apart, I didn't number them(darn it!), and I put them back in the wrong cylinders, so they were not supplying the right amount of fuel to each cylinder. New ones are at factory default(I assume), and so still don't supply the proper amount of fuel.
Any help at all would be greatly appreciated.
Theory: Again, I'm no diesel expert, so if this is way off, please let me know. Could the injector pump be malfunctioning in some way, where it is pumping the wrong amount of fuel to some of the cylinders? My thinking is that maybe the PO adjusted the shims in the injectors, to compensate for the pump. Then when I took it apart, I didn't number them(darn it!), and I put them back in the wrong cylinders, so they were not supplying the right amount of fuel to each cylinder. New ones are at factory default(I assume), and so still don't supply the proper amount of fuel.
Any help at all would be greatly appreciated.
There is a copper seal under each injector, but no shim. All the seals should be the same for each injector. The only shim/s in under the injection pump and should not be changed even if you were to buy an new injection pump.
From a hand out here at Cummins.....
Smoke colors
Black - indicates incomplete combustion of the fuel
Blue - engine oil burning
White - caused by raw un-burnt fuel passing into the exhaust system
Incorrect fuel injection timing
defective fuel injectors
low cylinder compression
Smoke colors
Black - indicates incomplete combustion of the fuel
Blue - engine oil burning
White - caused by raw un-burnt fuel passing into the exhaust system
Incorrect fuel injection timing
defective fuel injectors
low cylinder compression
D2Cat, I'm referring to the shims on the inside of the injector, under the spring.I don't know if those can be used to kind of fine tune the injectors.
Repair, Thanks for the smoke reference, and the suggestions as to what may be wrong. I guess it's time to get it to a shop, I'm not even gonna start playing with the injector pump. I can live with it burning a little oil, but it's really hard to start.
I just don't understand why it ran fine before I changed the head.
Repair, Thanks for the smoke reference, and the suggestions as to what may be wrong. I guess it's time to get it to a shop, I'm not even gonna start playing with the injector pump. I can live with it burning a little oil, but it's really hard to start.
I just don't understand why it ran fine before I changed the head.
North Idaho Wolfman
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Staff member
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The shims inside the injectors are for setting pop off pressure, they vary in height to make up for differences in the springs in the injectors, it has nothing to do with the injection pump.
If you took the injectors apart and swapped parts around then the pop off pressure is going to me wrong and it won't run properly.
If you have not set the valves properly that will also effect the running.
The low compression readings could be from the valves not being set properly or that the valves are just simply leaking.
If you took the injectors apart and swapped parts around then the pop off pressure is going to me wrong and it won't run properly.
If you have not set the valves properly that will also effect the running.
The low compression readings could be from the valves not being set properly or that the valves are just simply leaking.
Thanks, Wolfman! I didn't swap parts between the injectors, but I probably swapped injectors between cylinders. Thanks for letting me know that the injector shims weren't affected by the injector pump. I set, then double checked the valves, and I'm confident that they are set right, at .008" It's a new head, so I wouldn't think that the valves would be leaking, but anything is possible. I'm planning on doing a wet test sometime today, to see if the compression comes up. I suspect it will. If not, I'll back the valves off to.010", just in case my feel for "slight drag" on the feeler gauge is not accurate.
It has to be something I did wrong, I just don't know what it is. I'm convinced of that, because it ran great before I tore it down.
It has to be something I did wrong, I just don't know what it is. I'm convinced of that, because it ran great before I tore it down.
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This is from a Cummins 5.9 but the idea is the same.
Part #2 seals the injector to the head and is the same size on all of the injectors.
Part#5 is the shim that is used to adjust the injectors during a rebuild of the injector and when it was new to make the injector meet a standard specification.
Hope this helps.
Part #2 seals the injector to the head and is the same size on all of the injectors.
Part#5 is the shim that is used to adjust the injectors during a rebuild of the injector and when it was new to make the injector meet a standard specification.
Hope this helps.
