Export thread

I have a JD F525 48 in front mower, probably about 25 years old, powered by a PA540A motor.
It now won't start, it won't even turn over.
Before it stopped, it started to blow copious amounts of blue smoke and it was stopped. While still warm the motor would turn over slowly but not start.
Now cold it will not turn over even though battery and starting motor are in good condition.
Spark plug has been removed and still will not turn over, it cannot be rotated by hand.
I think that the motor is now seized and given the age of the mower the best solution is a new mower?

New engines are a lot of money. New mowers are even more.

Compare the cost of a new engine against the cost of a new mower of equal capability. If the rest of the mower is in good shape and a replacement engine is available, that might be the best way to go.

Sorry to hear that.

For the engine to seize it had to have an oil pump failure, oil filter blockage, run out of oil, or some other similar problem. So the seizure is simply a symptom of a greater problem. What I'm sayin is that it's probably not just a bore job with new piston and you're back in business. The whole engine is probably toast. I'd start looking for a new or used engine, built within the last 5-7 years. The newer engine technology is very, very good and there are probably several that are bolt-in swaps.

Are you sure that's the right engine model? every where i look i see that model using a KawasakI FC540v.

The engine model is right as it is the unitized engine. A real pain to remove and work on. It is even a pain to change the oil.

First I would remove the electric PTO in case it is seized.

Being F525 you are going to need to disassemble most of the back end to get even get the engine out so you can disassemble it for inspection. This is not for the inexperienced to do either.

As usual I am going to suggest you get a copy of the JD Technical manual for your mower.
Not cheap but worth every cent even if you decide not to tackle the job yourself.
Way too expensive to send it out .
With the manual in hand, check the parts prices
The blue smoke is a worry, the sort of thing that happens when a seal blows
After which the bushes run dry & siezure follows
If you are lucky just a polish might work if not there will be work to the crank bushes, new crank, piston , rod , seals & gaskets
Did a quick check and there seems to be no shortage of used ones around
And that list of parts would be near the price of a good used model

Also it might just be time to retire that 18+ yrs old mower and replace it with a new ZTR.

That engine hasn't been built for at least 25 years. If Deere does not have a replacement, which is likely, you are probably out of luck.