Flail Mower Is something wrong with my flail mower???

BigAl · Sep 29, 2005

I have a Ford 981 (7 foot)Flail mower for my 45 horsepower Kioti tractor . I bought it used from a party who new nothing about it and had never used it . I believe it might have been and old state surplus unit because it looked well used .After welding up any cracks , checking and replacing missing cutting teeth , checking the gear box for oil ,I thought I was all ready to mow down all the 5' grass on my old ranch . I hooked it up to my 3ph and fired it up . HOLY COW !!! The noise is unbelievable ! It also has a heck of a vibation that does not lessen as I come up to the 540 pto speed of 2400RPM . It is not the gear box but seems to be coming from the area of the cutting bar tube as it spins . It has a set of long teeth on it now . The previous owner also gave me a box full of new shorter teeth as replacment teeth . I resharpened all the existing long teeth as they were very dull . It cut better ,but the noise and vibation is still there . The bearings appear to be ok and the cutting tube is straight and since this is my first experience with a flail mower , I do not know what to do . I am ready to go buy a new bush hog to get the job done . It is extremely slow in the 5 foot pasture grass. If I let my PTO speed fall very much it will cook the three drive pulley belts at $60 a pop in about 20 minutes !!! I am in 1st gear on a 12 speed transmission so I am really creeping in order to get it to work at all . This grass is thick and heavy and I think that might also be a problem , but what is the deal with all this noise and vibation even if it is free wheeling ???? Is it the cutting teeth hitting the center tube as it spins ??? Any help or ideas ???
Big Al

TiminMN · Sep 29, 2005

The rotor is out of balance. When you replace a tooth your should also replace the one across from it. If you take the belts off and spin the rotor is should stop in a different spot each time you spin it. If left out of balance the bearings will go out shortly.

BigAl · Sep 30, 2005

Makes sense!!! I will give it a try. One more question if I may ? Is trying to resharpen dull teeth a good idea or is it best to just replace them ?
BigAl

KennyV · Sep 30, 2005

BigAl
You should not use a flail mower to cut tall grass. It over processes cut long grass and will require VERY slow travel speed, and lots of HP.
You can sharpen the knives if you don’t change their weight much… but a sharp edge is not what is cutting grass on a flail, velocity of the knife end, cuts whatever it encounters.
You must have all knives installed and they all must be the same length and type. You can get rough cut or finish cut knives.
Check that all hangers and loops with knives hanging down are the same length, if they are not you will have a balance problem…
Flails are nice but not designed to process tall grasses or tall weeds. Think of a flail as a hammer mill without a discharge screen. You have to regulate the quantity of input and keep the rotor balanced. High RPM is mandatory. KennyV.