Rotary Cutter Problems with my new Bush Hog 3008

[minner]

To set the stage I do some mowing for the public. I recently upgraded to a Kubota M7040 back last November and have slowly been upgrading my attachments as I could afford to. I sold my JD 390 flail and bought a new 8' BH 3008 twin spindle cutter. I was really excited about the purchase, having read nothing but good reviews on here, online sites, and at every dealer I called or visited. I eventually sucked it up and plunked down the cash. The first cutter had a gearbox with a bad vibe so it went back. I took the second cutter immediately to the field for a 18 acre job. Usually I can run my 6' cutter 5-7mph and leave a good cut. I expected the same from the 3008, NOT so. It cuts pretty hard but the m7040 has plenty of power although fuel consumption went up 20%. The cut quality is terrible on tall grass, weeds, and briars. It basically strips the leaves and leaves the stalks. On more "stemmy" material like Johnson grass, thistle, or milkweed it will leave about 50% of the material behind.
I contacted the dealer to which he of course recommend to drop down to L2, literally 2.1 mph. It cut better but not great and no one can mow that slow especially if you are trying to make money. I tried L3,L4, and H1 gears. Ranging from 3.0 mph- 5.0mph which coincidently is what it's manual recommends. All produced a similar result, of course getting slightly worse with ground speed. The odd thing was if you mow in reverse (same speed) it cuts awesome and leaves little behind, which is the way I cut the "tough" areas.
I called the dealer again today after another job and supposedly a BH rep will be calling me. We'll see. Here are some briars it missed Left side I mowed in reverse, right side in forward

 

[PoorPlowboy]

I run a BH 3008 on my 7040 same setup as yours. From the photos, I believe you have a 1000rpm bush hog on your 540rpm PTO. My 3008 with worn blades cuts almost finish mower quality on field grasses and light brush/briars. It builds a tall wind row in the center that leaves lasting stripes on a pasture.

Edited to add: I run the front skids 2-3 inches off of the ground and the tractor top link (hydraulic) in float so the rear of the hog follows terrain.

 

[minner]

I run a BH 3008 on my 7040 same setup as yours. From the photos, I believe you have a 1000rpm bush hog on your 540rpm PTO. My 3008 with worn blades cuts almost finish mower quality on field grasses and light brush/briars. It builds a tall wind row in the center that leaves lasting stripes on a pasture. Edited to add: I run the front skids 2-3 inches off of the ground and the tractor top link (hydraulic) in float so the rear of the hog follows terrain.

Wouldn't the pto shaft splines mismatch? The shaft is obviously 540 because it fits so it'd have to be a factory defect.
I basically have to drag it to make it cut which is hard on everything. At 3" off the ground it looks like someone was trying to cut it with their Murray.

 

[boggen]

3008 Series Rotary Cutters
TractorData.com Kubota M7040 tractor information

just showing 540 for both the rotatory cutter and tractor. and no 1000 rpm option.

you do have a slip clutch, and you most likely need to burn yours in (remove the varnish) off the plates. (get the slip clutch to smoke) and then you most likely need to set it correctly as well.
Tractor Attachments And Skid Steer Attachments For Any Tractor Or Skid Steer has a better video / detailed info of how to deal with a new slip clutch and set it up correctly.

was the blades installed correctly? they are not backwards or upside down are they?
i am guessing with a 2 spindle single deck, one turns counter clock wise, while other turns clockwise, who installed the blades? if it was an actual person, vs machine, i know i could have easily "whoops"

pull the PTO shaft off of tractor, and turn the PTO shaft manually, and see what way the spindles rotate. did they give you 2 clock wise, or 2 counter clock wise gear boxes on the spindles?

i guess last few sentences i should of ask first... if the blades overlap in the center like a finishing mower deck does? if they don't it really doesn't matter what way they spin. as long as cutting edge is in correct direction on blade, and you know you might have a little trail of uncut between the 2 blades.

does your tractor have option of different gears for PTO?

=============
EDIT: who adjusted the PTO shaft to correct length to fit your tractor? dealer or you? or no one? this is not due to mowing, but to keep shaft from falling apart and or binding up and causing a bent PTO shaft.

 

[minner]

I checked the blades, they are correct and according to the manual they are spinning correctly (left is spinning CCW, right is CW). The mower is 90% assembled from the manufacture. There is overlap of course, 3" on this model. I dont have different speeds on my pto, just 540.

 

[Turbys_1700]

Looks like your ground speed is too fast for your blade tip speed...
If you are running @ 540 check to see if the input shaft for your mower is 540 also...
Our Howse 10' BH has a 1000 pto input going into the main gearbox but we are running it at 540 from the tractor...
You will need to turn more revs and slow down to get the blade tip speed higher to get a better cut...

 

[minner]

I'll check that. Thanks
I would agree it seems like blade tip speed is the issue. Like I said I tried slowing down, all the way L2 which is a painful 2.1 mph. I will go out of business very quickly if I have to mow at those speeds. The manual states 3-5 mph ground speed.

 

[KiotiKowboy]

I'm still curious why it cuts great in reverse? What's the deal with that?

On second thought - maybe it's because you're moving dead slow.

 

[minner]

I'm still curious why it cuts great in reverse? What's the deal with that?

Thats my question too. Every cutter I've ever had cuts worse in reverse.

 

[boggen]

http://www.bushhog.com/uploads/documents/BHRotaryCutter3008partsPM-11.pdf
3rd page down, #13 denotes 540 or 1000 rpm central gear box option ........