John Deere 390 Flail mower

[leonz]

Hello and good evening, I wanted to let you know that you
need to adjust the top link correctly for it to work effortlessly
and also have a good cut.

Please use a small bubble level placing it on the guard over the
universal joint to adjust the top link to level the flail mower from
front to back with the bubble facing you.
The top link must be extended outward to level the gearbox and
by doing this the flail mower will not scalp.

The flail mower is now at its lowest cutting height PROVIDED the
top link is extended and the gear box cover is level.

Please block up the sides of the flail mower before you adjust the
rear roller as described below:

To raise the cutting height you loosen the 2 lower bolts and remove
the 2 top bolts holding the rear roller in place and set the rear roller
bolts in the next to last hole for the adjustment and you will have a
much better cut.
Please use a hydraulic car jack if you have one to adjust the rear roller
as it is heavy.

Leon

 

[Lineman North Florida]

Hello and good evening, I wanted to let you know that you
need to adjust the top link correctly for it to work effortlessly
and also have a good cut.

Please use a small bubble level placing it on the guard over the
universal joint to adjust the top link to level the flail mower from
front to back with the bubble facing you.
The top link must be extended outward to level the gearbox and
by doing this the flail mower will not scalp.

The flail mower is now at its lowest cutting height PROVIDED the
top link is extended and the gear box cover is level.

Please block up the sides of the flail mower before you adjust the
rear roller as described below:

To raise the cutting height you loosen the 2 lower bolts and remove
the 2 top bolts holding the rear roller in place and set the rear roller
bolts in the next to last hole for the adjustment and you will have a
much better cut.
Please use a hydraulic car jack if you have one to adjust the rear roller
as it is heavy.

Leon

Thanks for the information, that will help me out.

 

[Lineman North Florida]

LNF, that might just be the best 600 bucks you've ever spent. The deal that I got on mine was the best deal on one until you bought that one. That's a flail of a deal.

Yeah, after 10% buyers premium and 7% sales tax it was $580.50, sometimes you can get a deal at an auction other times if there are a bunch of dealers , the price get's run up as high as a new one.

 

[Oakfield1862]

haha, definitely a flail of a deal!

 

[Lineman North Florida]

Well I did a job with it today and thought it cut pretty good, did 10 acres and it has already paid for itself, I'm sure as I learn more about setting it up and experimenting a little I can fine tune it, looking at it this afternoon it looks like to me these l shaped blades can be flipped to use the other side to cut with, I'm learning as I go.

 

[joecdeere]

Yes they can be turned, and resharpened too, great winter project

 

[John0829]

I don't have the same brand of flail as you (Mott & New Holland) but on mine I will flip the knives and then replace them. I tried sharpening a set one time and it was a tiresome process verses the relatively reasonable cost of just putting on a new set from Flail Masters.

I keep a spare set on hand for each of my flails, just in case.

 

[Lineman North Florida]

I don't have the same brand of flail as you (Mott & New Holland) but on mine I will flip the knives and then replace them. I tried sharpening a set one time and it was a tiresome process verses the relatively reasonable cost of just putting on a new set from Flail Masters.

I keep a spare set on hand for each of my flails, just in case.

Thanks for the info, looking under it and counting yesterday there appears to be 3 rows with 14 attachment points on each row totaling 42 with 2 blades each so that would be 84 individual blades to sharpen, so I am definitely going to flip them first before replacing.

 

[leonz]

Your John Deere 390 flail mower is equipped with a 3 row finish mower rotor with side slicer knives.

The knives can be sharpened with a wet well grinder easily to prevent them from losing the blade
temper and hardness.

I have a wet well grinder and the same side slicer knives I bought in 1992 to replace the original side
slicer knives that is came with in 1982.

If you are sure you simply want to replace them you can but sharpening them is not difficult.

They become encrusted with grass dust and dirt and that affects the quality of cut and they need
to be soaked in hot water and washed and scrubbed with a steel brush in Dawn Dish Soap and this can be done in the off
season.

If the opposite side is sharp they have never been flipped so you can do that but you should plan on
having a replacement hanger strap and a new nut, bolt and washer for each mounting station.

If you have access to a steam jenny all the better as you can remove all the grass dust and dirt under
the flail mowers rotor shroud and the rear roller and the bolts as mower does create static electricity
and the grass dust will stick to everything everywhere.


Leon