John Deere flail mower questions

I just bought this at an auction for $428. I had been looking for a 6 foot rotary cutter to use for cutting weedy fields and such, but I bought this instead since the price seemed right. There is a plate on it with a serial number, marked Hecho En Mexico, but no model number. I am wondering if it might be an older 25a since it is 6-1/2' wide and seems to look somewhat like the ones I see in pictures. I am planning to run it with a Farmall 300 and hoping it will have enough power. The belt looks nearly new, but many of the hammers (if that's what they're called) are a bit beaten up. The auctioneer said that it had been gone through about 6 years ago, before it was purchased by the late former owner. I have never run a flail mower and I am wondering if there are any words of wisdom about what to do and not do. I know they don't like rocks, but the areas I will be cutting should have few if any as I have been being mowing them regularly once a year for the last 15 years. I can see some grease zerks and will make sure I grease it before I put it to work. I cut a test swath with the Massey 35 in the yard by the sawmill and it seemed to work OK, but that grass wasn't that tall anyhow. Thank you very much for any advice.
Zach

Folks here will jump on me for saying this but I ran an 8' Ford flail mower behind my Ford 1710 I took it real easy and mowed more often (every 3 wks.)so the grass wasn't to high. No brush just grassy field about 7 acres or more it took me about 3 hrs. +/-. I learned from folks here that a flail mower takes 4 or 5 HP / foot rule of thumb,I was way under that but it did a great job and looked almost like a lawn. I bought the mower from the Central Main Tech. Collage for $40.00 they were going to scrap it. I sold it and a ford 7' sickle bar mower for $800.00 to the folks that bought the property.

Looks like a 25A.I have one,they work great for clipping pastures.Not worth a damn in tall grass.Keep it well greased when using...the bearings will last a lot longer.

Zach, with sharp cutters those mowers cut good. They are very dusty to operate in dry weather but will not cut very well if the grass or weeds are wet.
You are rite about docks but be extra careful around wood as in stumps. Wood will strip the cutters off real quick.

Back when I was in collage Deere sent us a flail mower to try out. Had it on a 6400 and we cut everything with it from grass to grown up pasture with no problems.

Sharpen the knives and then hard face them. They will then last for years. I have done this on mine and the knives never get dull or worn. Hard surfacing is easy, but have to have an Oxy torch system.

Thank you all very much. I ran it for about 90 minutes today and it did fine, part of the time was mowing short grass on a path around the edges of some fields and part was mowing an area of mostly goldenrod that was as high as the hood on the 300. I will add and work on knives later this fall or over the winter.
Zach

No mower that I know of likes rocks

No mower that I know of likes rocks

I use a 6 1/2 ft wide Ford Flail mower and they do not like Brush ( as in Saplings, etc.).

If you really do get into some bigger stuff, you will be raising it up some because it CAN take some serious power..

I have brought my healthy JD 720 D to its knees on my flail.., but only in Very thick, tall grass.

They do a nice job and you will not need to over-lap like you do with a rotary mower..so you get a lot done and the job looks much better..