Injector and head help please!

[mikehenya]

Thanks to all for the great forum! I have been an avid reader for the last couple of years since i bought my 1702D! I apologize for the length of this post, but I need some help!
I attached a picture as well.

The questions:
I have a problem 1702D that has had several issues from the day I received it(details below), the latest is a head gasket. I decided to try replacing it myself since most of you said how easy it is. I got the head removed without incident, but when I started cleaning the gunk, I noticed a small crack in what looks like a part of the injector. I am attaching a picture, can someone tell me if this is a problem (and what it is).
2nd question, do I need to clean off all the silver "paste" from the old head gasket? If so, what would you guys recommend to remove it with?

History of issues:
In case you need a history to diagnose the cause, I bought the tractor from out of state. When it was shipped, the dealer emptied the oil and fuel. The truck line decided to put in some fuel and drive it off the truck and onto the dock when they switched trucks. Low and behold it seized up the day it was delivered (yes, I put oil in, but didn't know about the move till it seized and I called the shipper). The truck line and shipper went back and forth about liability and I got stuck with the tractor. After threat of a law suit, they paid to rebuild the bottom end. I added money and had the local J D dealer do the work. After 9 weeks I got the tractor back. The tractor ran for 3 weeks after the rebuild and blew the head gasket. The dealer admitted they were in a hurry and may not have properly flushed the engine! They rebuilt it again (new bearings etc... ) at no cost, other than the 8 additional weeks it took to do. I got the tractor back near winter. I used it a few times to plow the drive. Once spring came around, it ran for 3 weeks again ( that means I mowed 3 times with it)! It did not overheat the first 2 times, but the 3rd it started to heat up. I called the dealer back, threw a fit and they worked on it a third time!
The good news is, I mowed as much as I could last year, and it worked great.
Once spring rolled around, the tractor started to lose water through the exhaust. While removing the head, the center 4 bolts were only torqued about 1/2 of what the outer ones were. Obviously I can't prove much, and it has been to long to do much, so I am going to attempt it myself this time!

Thanks!!

 

[rock2610D]

I believe that is the front chamber. The fuel injector squirts into it and swirls the fuel and pushes out thru those holes. If the other ones do not have the crack, which I suspect they do not, it needs replaced. Copper washers & rear chamber should be replaced to if it were me.

I would also order an NEW head gasket. Do not reuse the existing one it may not torque right. I suspect the gasket sealer on the head gasket is there because dealer reused old head gasket. A no no in my opinion!

As to loose head bolts!! After you torque the head down and everything is back to running order ldle motor for about 1/2 hour and retorque head again. Then after say 10 hours or running torque again. This should have been done the first time and second time the dealer had the head off, to rebuild lower end. I suspect that not having the head properly torqued caused the overheating problem. IE combution gasses going to radiator??

The losing water thru exhaust! Well a bad head gasket could put water into the cylinder and piston is pushing water out the exhaust. Or a cracked head!!! I would have head magnafluxed to make sure there are no cracks. If no cracks then the loose head bolts allowed the water to flow into cylinder and then out exhaust.

Those swirl chambers could be a pain to get out!!! While head is at machine shop have them remove the swirl chamber and install a new one.

 

[larso1]

Interesting problem. As Rock2610D mentioned, absolutely get a new head gasket, they crush to small extent. And retorque the head bolts after running a short time...and make sure the motor is cold when you do. Best to back the bolts 1/4 turn CCW before torquing in the CW direction to overcome the initial friction (stiction). Before installing the new head gasket though I would sure check to make sure the head is flat, not warped, with a steel straight edge. Otherwise it's all for nothing if warped. Then you just have it machined flat if it is. Not many people (or shop manuals I've read) recommend putting any kind of gasket sealer/cement on head gaskets either, although a diesel mechanic I know says he sometimes sprays both sides of the gasket with hi-temp aluminum paint. Don't know when he decides to do this though. The copper with steel head gasket on my Iseki has thin teflon rings embedded around each of the coolant holes (they can scrape off easily during installation) so I know it's installed dry. And make sure you torque the bolts in the correct order (according to the shop maual), usually from the center to the outside, and in stages (3-stages?) of partial torque to the final value.

On the injector tip, I don't know. Those two curved lines (if that's what you're talking about) are almost too symetrical and perfect to be cracks. But as Rock mentioned, look at the other injector to be sure. Good luck, you can do it. I did, and that means anyone can).

Bill

 

[larso1]

Oh, and one other thing I forgot. Make sure you check the valve clearances after you re-torque the head bolts. They could become alarmingly tight if the head gasket crushes at all.

Bill

 

[mikehenya]

Thanks for the tips guys! The new gasket from Hoye showed up today. The cracked "swirl chamber" in the picture is the only carcked one of the 3. It is in the center chamber. I will clean off the old teflon or whatever from the heads tomorrow. I think I will make a new post about the swirl chamber. I really don't want to have the JD dealer that made a mess do anything else, but they are the only shop locally that will touch the Yanmar.
I think I am in over my head with the history I have with this tractor. I am worried it will keep failing every time I use it! Is the 1702 a dud model? I am running a 5' finish mower with it, thats all I need is a 4wd mower. The 5' finish mower isn't to big for this model is it?

 

[1danny]

Thanks for the tips guys! The new gasket from Hoye showed up today. The cracked "swirl chamber" in the picture is the only carcked one of the 3. It is in the center chamber. I will clean off the old teflon or whatever from the heads tomorrow. I think I will make a new post about the swirl chamber. I really don't want to have the JD dealer that made a mess do anything else, but they are the only shop locally that will touch the Yanmar.
I think I am in over my head with the history I have with this tractor. I am worried it will keep failing every time I use it! Is the 1702 a dud model? I am running a 5' finish mower with it, thats all I need is a 4wd mower. The 5' finish mower isn't to big for this model is it?

The front pre combustion chamber is no longer available new, but I may have a used one. Drive the chamber out with a socket ( just a bit smaller than the chamber ) and hammer from the piston side of the head.

Danny

 

[California]

I really don't want to have the JD dealer that made a mess do anything else, but they are the only shop locally that will touch the Yanmar.

It sounds like you have good reason to fear that Deere dealer!

Yanmar engines are also used on ThermoKing refrigeration units for semitrailers. You will probably find a Yanmar engine specialist if you ask about ThermoKings at a trucking terminal. Also, a truck shop could probably refer you to an injector shop who can get you running again if you obtain the parts. And Yanmar makes marine engines for powerboats and big sailboats in case you are near water.

You aren't limited to the world of farm equipment.

 

[larso1]

Also try Welcome to Diesel Electric Service & Supply! (Diesel Electric Service in Utah). They sell Yanmar injection parts and probably a lot more, and it's all new stuff. I got all my Isuzu top end rebuild parts from them and my tractor's motor is a 1979. Jim Hiner is the guy in parts to ask for. You'll need the model number and probably some other numbers off the motor.

Bill

 

[mikehenya]

Thanks for all the help guys! I really appreciate the tips!

 

[irwin]

As to loose head bolts!! After you torque the head down and everything is back to running order ldle motor for about 1/2 hour and retorque head again. Then after say 10 hours or running torque again. This should have been done the first time and second time the dealer had the head off, to rebuild lower end. I suspect that not having the head properly torqued caused the overheating problem. IE combution gasses going to radiator??

The losing water thru exhaust! Well a bad head gasket could put water into the cylinder and piston is pushing water out the exhaust. Or a cracked head!!! I would have head magnafluxed to make sure there are no cracks. If no cracks then the loose head bolts allowed the water to flow into cylinder and then out exhaust.

Those swirl chambers could be a pain to get out!!! While head is at machine shop have them remove the swirl chamber and install a new one.

Yes! the cost of machine shop to have head magnafluxed is well worth the piece of mind, especially after that string of repeat problems you covered in your first post! Do let the machine shop replace that cracked chamber even if you have to supply the part.
You have a chance to do this right finally, don't let a few dollars push you into cutting corners!! After all you've been through, you deserve that tractor running right.

good luck....25 years in an auto repair shop, tells me this could be done, but do it by the book- wouldn't hurt to get new head bolts either....also while we're checking the head for warpage, go ahead and check the block, it's a slim chance of damage, but it wouldn't be the first time, most likely improperly torqued head bolts are root of THIS failure...but....