Curious, there is a Kubota 2900GST I found that is will used (2500 hours). The owner has had it for four years and originally purchased it with a blown head gasket. He claims a mechanic repaired it professionally and he has been using it for every day duty since.
How reliable are these? I'm wondering why it blew a gasket in the first place. At $5000, it's priced well below anything else I've seen.
Are you asking how common are headgasket repairs? If so I can answer as a mechanic and long time shop owner. Head gasket repairs have always been one of the staples of any mechanical shop that does engine work. Mechanics fight for those jobs. It is a common malfunction, straightforward to repair as good as new, and labor intensive. You do the work standing up instead of laying on your back. Technically, there's some benchwork which is nice to do too. That's because when the head is off is a good good time to throw in some machine shop work on the valves and head face, and as a bonus the mechanic and the shop normally gets a split on that work too. The result of a good head gasket/upper end repair is a motor that runs better and is more reliable than new. It runs cool again, and probably has a few more HP.
So mechanics love to do head repairs. It is clean work, done on top of the engine, pays very well, and results in a satisfied customer. When a head gasket blows it typically doesn't hurt the other parts of the engine. It's a little costly to do it right because each procedure adds up, but the result is not too expensive for what you get. That's a nice balance between cost & benefit all around. Repaired right, the engine is actually better than new and more reliable.
But because there is that additive expense factor.... and because nobody can really tell afterwards whether or not all the work was done right or even done at all...Well, head work is also a job that can be done too cheaply by lazy mechanics looking for a fast buck by just taking off the head and replacing the gasket without any machine shop work on the head face, valves, or cooling system. The downside for the customer is that work done like that will hold up for awhile, but is pretty much a guarantee that the head gasket will fail again in the same way. The upside is that it can be fixed again....and this time correctly.
BTW, overheating an engine is the most common cause of head gasket failure. It occurs when the heat either warps the head which allows coolant and oil pressureto bore a connecting hole in the gasket.... or by heat expansion loosening the bolts that hold the head tightly resto of the motor and again leaking coolant and oil into where it shouldn't go.
But head gasket failure isn't always due to overheating. Some head gaskets simply fail. I say that because I've seen plenty of engines - and even owned some - that I am absolutely sure were taken care of properly that eventually needed headgaskets.
To answer the question you didn't ask, if it was professionally repaired there will be a repair ticket that lists procedures and parts used. If the tractor owner doesn't have it, the shop will. Or at the very least the mechanic should be able to remember that job and be willing talk about it in detail. So all you have to do is ask whoever did the work. I've never known a good mechanic or shop that didn't keep at least some sort of records. It's all part of the definition of "repaired professionally" as your seller is claiming. Shop owners have to keep job records for legal purposes anyway, and accurate repair records are just about the best advertising that a mechanical shop can have. Don't be afraid to ask at any repair shop about any job that they did. As an owner, I had people come in every day with that question about work done on a vehicle they were thinking of buying. It's common.
rScotty
