B7100d with mower questions

[markwelle]

Hi all. Newer tractor owner (old tractor, new owner!) with a quick question about my brush cutter/mower. It is an old Woods Billy Goat M4 PTO mower. I believe it's more of a brush cutter if I'm not mistaken...and my Kubota is a B7100d from the late 70's/early 80's, with a FEL.

1) How do I remove the blades so I can sharpen them a bit? I understand from a previous post that they should be flat at about 1/8", but mine are rounded completely the thickness of the blade, so a little honing is due...I see there is an access cover on the back of the deck that lines up with the pin and bolt at the blade. Do I just remove the bolt? How does the pin come out/blade come off?

2) Based on my tractor, I'm told that brush cutting is best done at WOT, PTO gear 1, and the tractor speed set accordingly to my terrain and quality of the cutting action behind me. But I've also been told about this magical 540 RPM setting. I'm nearly positive that refers to the PTO speed, not the tractor engine, but not sure...and how do I figure out the PTO RPM's? I have about 6 acres to cut a 48" strips, so the faster I can operate, the better, but I don't want to stress the tractor/implement out too much either...trying to find that nice balance...does the speed of the PTO make a big difference in the cutting ability of the mower, or is the speed of the tractor more important? If I went to speed 2 on the PTO, would I reduce the throttle on the tractor accordingly?

If it matters, the field native grasses are really tall this year. After 2 months of rain nearly every day, I'm looking at 24-30 inch tall grass covering my entire property that needs to be cut down to about 6"...any suggestions or tips?

Thanks in advance!

Mark

 

[Hondarancher4435]

I had the same setup myself I can help with some of your questions. Yes the whole In the deck is to unbolt and remove the blades.

The combination of the m4 and b7100 is a good combo however it is about all that tractor can handle you will have to cut in low range for sure if it's 3-4 foot high thick stuff it will be slow going in first gear if the grass is a little thinner or been cut before 2-3 gear may work okay.
That mower is made to run on the 540 pto setting as are most implements you will ruin the gearbox running it on a higher speed. It's hard to find exactly 540rpm since you have no tach but I would always run the throttle all the way up and then back it down 2-300rpm which always worked well

 

[Russell King]

When you take the cover off the hole you will have to rotate the mower by hand to align a nut with the hole. You will have to get the correct size socket (probably around 40 mm or 1.5 socket) in the largest drive (3/4 or 1 inch drive you have. It will be tough to remove.

The bolt will be keyed into the mower somehow so it will not rotate when removing the nut. The bolt and blade may fall off when the nut is removed.

I suggest that you get a new set of blades to ensure you have the correct set for the mower. If you don't have the part manual for the mower, call the manufacturer after you get the blades off and they will want to know what number is stamped on it. They can provide you a part number from that or possibly from a serial number on the mower.

I would not trust that the blades are correct on an older mower.

When installing them you will need to torque the nuts to the proper value. You may need to buy or rent a torque multiplier to do this with a normal 1/2 drive torque wrench.

 

[Bulldog]

First off I wouldn't suggest running the pto in 2nd gear. Yeah it will cut thru the grass like a tornado but you'll be risking damage to the cutter or even danger to anyone around if the cutter breaks. Even if you throttle down you're taking a chance on lugging the engine which will lead to other issues like overheating.

Blades, I would check for damage and if good go ahead and use them again. Just remember when sharpening try to keep them equal. They are balanced and it doesn't take much difference in weight to cause vibration. In most cases blades are pretty cheap so it might be money well spent to get a new set and have a fresh start.

 

[OldeEnglish]

I have the exact same Brush mower as you and it does a great job. For RPM's, I use the foot throttle and it seems to cut very good with the throttle level with the foot board. If I tackle something really thick I'll run it wide open. I cut a lot of maple saplings that were up to 1" thick and sometimes I had to run it wide open. With tall field grass your 7100 will tear through that like butter. For gear speed I usually used 2nd low and always had on 1st PTO speed. I wouldn't worry about sharpening the blades, mine are dull and beat to death and it still cuts grass absolutely fine.