520LXI low hour failure

[Theroundhousernr 590]

 For those of you who saw the 520LXI on craigslist in Jersey listed for a few days or for those just interested in them, I wanted to show you some pictures of the one my buddy just picked up. The add listed something like 520lxi. Only 400 hours on working meter..... Head gaskets blown, but I have everything cleaned and ready to assemble. Comes with 60" deck. The pictures do indeed make this thing look like low hours. So I call my friend Randy and off he goes to pick it up. When he gets there the cylinders are covered in neversieze! What a mess! NOTHING is clean and ready to assemble in anyway and he really wonders if the neversieze is to cover up rusted cylinders from moisture. Non the less , it seemed to be a good deal for what he got and it is indeed only a 400 hour machine.

 

  Now to the wierd part and I am hoping there is someone out there that can take a guess at what happened. We were both stumped when looking at the add, why there would be a head gasket failure on such a low hour machine. There was a lot of grass in the radiator area which was a first thought. I stopped over last night and we thought , lets wipe that neversieze off with some rags..... Cylinders look ok, not to bad. Then on the side I was wiping off I notice a nice chunk missing from the top of the cylinder. It almost looks like a factory defect maybe. The other cylinder has the starts of it. Is this the cause of a head gasket failure and then continuing to use it or is this a factory defect? Here are some pictures of what I am poorly trying to explain....

[doc724 925]

First, I want to say that I am glad I have the air cooled version.  That liquid cooled set up looks awful cramped.  Now, reaching back into my foggy memory cells, I don't think it is a defect.  I think you have a corrosion/heat related problem.  As I remember, I think (thought) there was a phenomenon in IC engines called detonation corrosion.  Basically you have a condition where small pockets of liquid get trapped, turn into steam then collapse, the resulting collapse starts to make local corrosion sites.  I notice in the pix that the defect is closest to the exhaust valve which would be the hotter side which would make sense.

 

All my corrosion engineer contacts have retired or passed on.  However if you really want to dig into this, look for a paper by Dr. Robert Baboian in the ASTM Journals of Corrosion.  Date would be around 1978.

[Theroundhousernr 590]

Has me puzzled. I have heard of cavitation on diesel engines due to the micro flexing of the cylinders at high rate creating air pockets around the cylinders, which then as you say steam starts to pit away at them. But as I understand it, that was really only a diesel issue due to high compression. The way to monitor that in a diesel engine is watching the nitrate levels and additives. The real question is , is that what has happened here and how is that possible on such a low hour motor?  Could be heat I guess and it is spinning that big 60" deck. I have searched a bit on here and turned up nothing in the way of head gasket failure or cylinder deterioration.

 

 Was wondering also if the gasket some how failed and left exhaust gas into the cooling system area and burned away at the aluminum.

[WH nut 553]

1 hour ago, Theroundhousernr said:

Has me puzzled. I have heard of cavitation on diesel engines due to the micro flexing of the cylinders at high rate creating air pockets around the cylinders, which then as you say steam starts to pit away at them. But as I understand it, that was really only a diesel issue due to high compression. The way to monitor that in a diesel engine is watching the nitrate levels and additives. The real question is , is that what has happened here and how is that possible on such a low hour motor?  Could be heat I guess and it is spinning that big 60" deck. I have searched a bit on here and turned up nothing in the way of head gasket failure or cylinder deterioration.

 

 Was wondering also if the gasket some how failed and left exhaust gas into the cooling system area and burned away at the aluminum.

Im with you on this, Im betting they didn't use antifreeze or had a bad cap and caused cavitation, Or the tiny air bubbles that pop and ate away the metal.

[Phatboy 565]

He may have been one of those ppl that starts his machine up in winter at full throttle which can cause that,,, the metals have not had a chance to heat and expand and apply enough pressure on the gasket so it seals properly... That is why it is important to start at low rpm until then engine can heat and expand the metals to create the tight seal required ,, other wise it just blows out the gasket and creates havoc on the part of the engine where the combustion and gasses are escaping the cylinder...i've seen it many times,,, hope that helps buddy !! Oh and FYI,, never use never seaze on an aluminum alloy metal it actually will eat away at the metal and then you will end up with a paper weight,, that is how NS actully works and is designed to be used on hardend metals not alloys,, i would wipe that off asap,,, well thats my 3 and 1/2 cents haha,,

Edited February 20, 2016 by Phatboy

[Theroundhousernr 590]

4 hours ago, Phatboy said:

He may have been one of those ppl that starts his machine up in winter at full throttle which can cause that,,, the metals have not had a chance to heat and expand and apply enough pressure on the gasket so it seals properly... That is why it is important to start at low rpm until then engine can heat and expand the metals to create the tight seal required ,, other wise it just blows out the gasket and creates havoc on the part of the engine where the combustion and gasses are escaping the cylinder...i've seen it many times,,, hope that helps buddy !! Oh and FYI,, never use never seaze on an aluminum alloy metal it actually will eat away at the metal and then you will end up with a paper weight,, that is how NS actully works and is designed to be used on hardend metals not alloys,, i would wipe that off asap,,, well thats my 3 and 1/2 cents haha,,

Dont get me started on the never seize .... The guy he bought it from I think smeared it on to cover up what was there. That stuff is a mess!

Also cavitation generally looks like pitting, almost like rust pitting. So I dont feel that is case here but what do i know.... Thats why I am kinda hoping someone may have seen this before on these kawasaki engines.

[shallowwatersailor 3,214]

I think I would check out the JD forums for this issue as they used the same engine. I know that some models suffered the same malady of the plastic timing gear

[clip 185]

17 hours ago, Phatboy said:

Oh and FYI,, never use never seaze on an aluminum alloy metal it actually will eat away at the metal and then you will end up with a paper weight,, that is how NS actully works and is designed to be used on hardend metals not alloys,, i would wipe that off asap,,, well thats my 3 and 1/2 cents haha,,

 

Not to start a fight, but I believe this to be misinformation. I've never had issues using Loctite N-5000 or any other nickel-based anti-seize compound on aluminum. I use it at every spark plug change where the carbon steel plugs get threaded into the aluminum head, and we use it religiously in nuclear where stainless fasteners get torqued into aluminum threads as well. In my experience, there has never been a reaction between the compound and aluminum. Couldn't find any in online searches either.

 

Again, not calling you out, just saying I've yet to see an issue where the compound affects aluminum. When someone uses too much on any material and it gets baked on and gummy, that's a different story.

[DennisThornton 4,771]

I'm not debating anything, merely commenting that I've used nickel based anti-seize for 40 years or so and if it caused a problem it I'm not aware.  I never had an issue removing anything that had anti-seize on it.  Only what didn't have it.  It did recently notice for the first time an aluminum based anti-seize that prompted me to Google a bit.  There's now far more types than I knew of.  Must be a reason (well, besides marketing and more sales...)

[Phatboy 565]

Here is just one of thousands of articals on never seize,, just google never seize bad for metals,

K

[Phatboy 565]

Here is link http://www.fjrforum.com/forum/index.php?showtopic=142977  sorry for extra post link wouldnt go onto last post for some reason,, this is the artical for the above pic..

Edited February 21, 2016 by Phatboy

[clip 185]

Phatboy, thanks for the link. Was a good read, but it's interesting to that the poster said plug manufacturers stated their torque specs with dry threads. I guess since they've already played a coating on the threads they torque more consistently than bone dry. I'd still be hesitant, but do agree lubed thread torque specs are different than unlined. Also noted that the article stated excessive anti-seize was used.

 

On the galvanic corrosion/dissimilar metal issue - there has to be an electrolyte in contact with the dissimilar metals, usually water in most galvanic corrosion cases. Taken from Wikipedia's page on the subject and agrees with what I've learned in my studies:

"Ensure there is no contact with an electrolyte. This can be done by using water-repellent compounds such as greases, or by coating the metals with an impermeable protective layer, such as a suitable paint, varnish, or plastic."

 

Since anti-seize compounds are nickel or copper particles in a grease suspension, I doubt you'd see much in the way of galvanic corrosion occurring.