OutdoorKing Repair Forum Forums General Discussion Forum Off Topics My first and last experience with a Kirby-Lauson!!

I recently put together five sturdy old Southern Cross mowers with KXD ECB engines and got all 5 of them going without too much trouble. There were a few minor hiccups, one leaking a bit of oil, another burning a bit of oil, another one flooding. But nothing too serious and all problems that were easily ironed out.

About two weeks ago I took possession of an old H. G. Palmer mower with a Kirby-Lauson VK-30 engine. In contrast, everything about this mower and engine proved difficult. It was so compact it was like working on a modern whipper snipper. However on pulling the engine down I was amazed at how clean the parts all were and everything inside was in top condition. Valves and rings good, gears good, bearings good. It looked new in fact. However I was a bit concerned about the quality of material that these engines are made from. Believe me when I tell you that the stuff coming from China today is far superior. Despite their reputation for being built here in Australia during the 1960s, these Kirby-Lauson engines were clearly made in a hurry and out of junk metal.

I put the mower all together and even painted it as there were no oil leaks to be seen.

Kicked it off and it started first go, ran flat out for about 5 seconds then gave a rattle and clunk and stopped dead. I could not start it again. The starter cup had come loose and I thought that must have been the noise I heard.

Then began the process of trying to track down the cause. I pondered over the carby settings for a long while. Changed the plug. Cleaned the points, checked for spark. Everything looked okay until I removed the inspection plate and took a peek. The valves were not working when I turned the engine over! So I drained the oil and found two gear teeth in the oil pan. OH NO!!! Then shook the crankcase and heard it rattle! Straight away I new something catastrophic had taken place.

Here is what I found. That metal is as weak and brittle as chalk. No wonder it snapped. I wonder if somebody before me has soaked these parts in acid or something corrosive? Or maybe they have just gone brittle with age.



Not much hope for this mower now and it will be impossible to find replacement gearing. Think I will just scrap it and sell it off as parts to recoup my losses. I spent about $300 on this mower (didn't seem that much until I added up all the receipts!). I'm sticking with Southern Cross from now on, especially the models that used their own engines. Manuals for Kirby-Lauson are also rather vague and difficult to follow and they do not give the necessary information, unlike Southern Cross manuals which even provided detailed instructions for the home user on how to change the rings. Kirby-Lauson get the big thumbs down from me.

Hello vint-mow
I am sorry to hear your view on this.
For me, the Lauson design was always a good one.
A VK30 served my family for decades and never missed a beat.

There must be a reasoned explanation for this failure.
It is catastrophic.

--------------------
Jack

Jack, The metal on that gear shaft is so brittle you can break it away with your fingernail. I can only guess someone had soaked it in acid prior to me buying it.

Rang a local mower shop and he tells me he has a VK-30 engine in working condition. Might take a look at it and buy it if he doesn't want too much for it.

I can't get very inspired by this mower or its engine if the truth be told. I guess it is just too "American" for my tastes. I am definitely a Southern Cross man, and then I am picky. I only like the ones with their own ECB engines. Some of the 2-stroke engines on the SC's were not much good if the truth be told.

I'm not convinced the metal is the problem, over revved engines will do that, something was not right for it to rip all those teeth off

Showed it to a mechanic mate. When I told him how old it is and showed him the state of the metal, he just laughed. "Metal fatigue mate!" came the reply. "Same reason old plane wings drop off."

He reckons all the years of heating and cooling, things being under pressure, then not under pressure, swimming in mineral oil for the past 50 years, it all takes its toll. And considering this is only a very light, porous alloy material ("sh$$ metal" he called it), eventually it got soaked through, possibly following a flaw in the casting that had been there ever since day one, and you see the result. Basically it had to happen sooner or later, and I guess with a reconditioned engine, all sealed up with new gaskets and oil seals and new oil, the extra stresses were just enough to cause it to break.

Yes it certainly is a combination of fatigue and a casting defect. As cast components can last a lot longer than that.

Yes LRT, the metal on that camshaft had turned to chalk, literally. It must have broke suddenly, causing it to go crooked just long enough to strip off the teeth. That is why the teeth are only stripped off one side and the other side is okay. All this would have happened in a couple of seconds.

Never ever seen or heard of this being a problem with Kirby engines having worked on them for many years . They run for ever if looked after, vk30s main cause for failure was neglect on the owners part for not changing the oil. With a pressure fed oiling system for crank and con rod it did cause failures for lack of oil, unlike the splash system on the Briggs in its favour vk30 has a more durable cast iron bore than common alloy cool bore Briggs they're a good motor when regularly serviced