# Can't Get Smooth Cut with Disc Mower



## JimG

I have a John Deere 265 disc mower which I believe is the same as a Kuhn GM700. The mower is mounted on a dolly and I pull it with a Kubota 90 HP tractor (M9000). I use the mower to cut Bermuda grass hay – Coastal and Tifton 85. I have had the mower for four years now and I have never been able to get a smooth cut. It leaves random patches of uncut grass. Recently we cut some really heavy Tifton 85 that had gotten taller and more mature than normal because of wet weather delaying cutting it. The cutter made a mess. There is a lot of uncut grass or grass that is cut about half way leaving 8 to 10 inches uncut. I have tried everything to get it to cut better. I’ve tried mowing slow (around 4 mph). I’ve tried mowing faster (around 6 mph). I’ve been very careful to overlap passes and I make sure the blades are in good shape. Even with brand new blades it still leaves the field rough. When mowing I lower the mower mainframe to the ground via the dolly lift then I lower the cutterbar to the ground and put the tractor hydraulic control in float position. No matter what I’ve tried I still get a rough looking cut. My fields are a little rough in spots and sometimes we’ll have a few gopher mounds and fire ant mounds but even where the ground is smooth I don’t get a consistent smooth cut. There must be something I’m not doing right or something wrong with my mower or setup. If anyone has any suggestions or advice I would appreciate it. Thanks.


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## sedurbin

Not familiar with that exact cutter, but it almost has to be belt or clutch slippage.


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## NDVA HAYMAN

I'm with Sedurbin. There has to be something slipping somewhere. Are the areas that are rough in the same location? In other words, are the areas that are left rough the same on each pass that you make? Mike


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## country boy

I have a jd 260 mower ( same mower just older ) have found when the grass is thick I have to run the mower a little faster than 540 rpm about 600 make sure the belts arent slipping and mayby slow to 3.5 mph. I know it cut better on my 50hp than it does on my 85hp


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## JimG

No, most of the time it seems to be random and not necessarily in the same place each pass. There was one area my last cutting where the grass was extremely thick that it consistently didn't cut every pass. I have tightened the belts per the manual. Is there some other place where slipping could occur?
JimG


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## mlappin

Inspect the belts closely, if they are glazed, regardless of how tight they may be they can slip.

If the belts are glazed, replace with OEM belts as sometimes OEM belts have a slightly different angle on the sides or the height of the belt can be different. While a standard A, B or C belt may look the same as a OEM, sometimes their is a subtle difference and a standard belt just can't transmit the same power as a OEM belt.

Also look closely at how they ride in the pulleys, they should not ride in the bottom of the groove. If new belts still ride in the bottom then excessive belt slippage has worn the pulleys and they will need to be replaced regardless of what belt is used.


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## geiselbreth

put honey on belts also u might want to tilt the cutter bar over a little also u didnt mention if the hay was blown down both of my mowere miss a little if the hay is blown down krone 283 and 3200 easy cut vemeer 605 m jd 338 with hoelscher


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## JimG

geiselbreth said:


> put honey on belts also u might want to tilt the cutter bar over a little also u didnt mention if the hay was blown down both of my mowere miss a little if the hay is blown down krone 283 and 3200 easy cut vemeer 605 m jd 338 with hoelscher


On my last cutting some was blown down but I've had the problem of not getting a smooth cut before when it wasn't. Not sure what you mean about putting "honey' on the belts? I will try tilting the cutter bar and see if that helps. I've been running with the cutter bar level. Thanks for the reply.
JimG


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## NDVA HAYMAN

He was talking about putting honey on the belts to make them grab and not slip. Never done that and you should not have to if you have the correct belts. Still think something is slipping or maybe a bad bearing. Hard to tell. Is there a chance that someone could walk beside your mower and maybe see what's going on. I know it's not the safest thing to do but if you go slow, maybe someone can see something that you can't. That's why I work a lot of young hired hands. LOL. I run disc binds (JD) and mower conditioners and am not familiar with your particular mower. Mike


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## lewbest

Just a thought (untested; just a theory) you might run it a short distance in heavy grass & then (shut down of course) feel of the belts & pulleys & see if they feel hotter than you'd expect indicating slippage? Might feel of the bearing housings also for excessive heat?

Lew


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## Customfarming

Kuhn mowers do not cut bermudagrass cleanly and leave streaks all over the field even with brand new blades. We have tried running longer blades, tilting mower down, higher rpms, and speed but still the same result with out any improvement. We cut coastal, T-44, and T-85. This is why we are selling our kuhn mower. Our neighbors complain about the same thing and are going to krone mowers. You will be amazed at the difference with the krone mower than the kuhn.


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## kyfred

Have you replaced your knives, or check to see if they are on the right disc's. Make sure the arrow on the knives are pointing in the direction they are supposed to be traveling when the mower is cutting and make sure they are sharp. Also when we bought our Krone disc mower the dealer had installed a set of dome shaped knives that he said was for rough rocky ground. It didn't cut very good at all and if the hay was down it didn't want to cut at all. We put the regular knives on it that are directional and they cut good and the mower doesn't pull the tractor as hard as the dome shaped knives. Just a thought in case something is not slipping. Sounds like something slipping though. Good Luck


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## Bradbid

That's bugs the snot out of me to see uncut hay left in our fields. We've got the same mower and I have done the following to clean it up. It works good if I'm the one mowing hay. If you're talking about long leafless stems left in the bermuda, then slow your ground speed, and tip the mower further forward. It will make all the difference in the world. I never run over 540 rpms. Using a JD6310 tractor and the same mower, I run in C-1. I can't remember the mph. It takes longer, but the hay is all the same height when I get done. If you are talking about long green strips, parrallel to your tire tracks, then your mower is running too far to the side of the tractor for you to line your tire up on the bare ground.

If you can't wiggle the sleeve on the bolt that tightens the belts, then they aren't loose. IMO, if they're slipping at all, you'd smoke them in thick hay.


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## JimG

Bradbid said:


> That's bugs the snot out of me to see uncut hay left in our fields. We've got the same mower and I have done the following to clean it up. It works good if I'm the one mowing hay. If you're talking about long leafless stems left in the bermuda, then slow your ground speed, and tip the mower further forward. It will make all the difference in the world. I never run over 540 rpms. Using a JD6310 tractor and the same mower, I run in C-1. I can't remember the mph. It takes longer, but the hay is all the same height when I get done. If you are talking about long green strips, parrallel to your tire tracks, then your mower is running too far to the side of the tractor for you to line your tire up on the bare ground.
> 
> If you can't wiggle the sleeve on the bolt that tightens the belts, then they aren't loose. IMO, if they're slipping at all, you'd smoke them in thick hay.


Thanks for your input. That's the way I have tightened the belts - tighten the bolt until the sleeve won't move. I have both problems you describe - stems and green strips. I will try tipping the mower forward more but how do I adjust how far the mower runs to the side of the tractor. Of course mine is not attached to the 3-point lift but is on a dolly. In addition to these two problems I also have areas of just uncut grass, not strips of green or stems. It behaves like the belts are slipping but I don't think they are. After looking at the parts breakdown on the John Deere website today I am wondering about the clutch on the PTO driveline. Don't know how to check it but I may just replace it and see if it makes any difference.


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## Bradbid

I don't know how to adjust the mower over on a dolly, it's easy on the 3 point hitch. We've had our mower for 7 years or so and I've smoked the belts once, and my brother did the same two weeks ago. I've been told by more than one person, if you smoke the belts they'll have to be replaced. Not so apparently. We have not replaced the belts on ours, I couldn't even tell you the last time we tightened the belts. Ours has never left completely uncut hay in the swath of the mower like you are describing. I'd give that bolt a couple more turns, or ten. I think I gave ours a couple extra turns the last time too. If you haven't taken the belt shroud off, I'd recommend doing that so you can tell if one or maybe two of the belts are stretched further than the other. Unless you've sprayed oil on the clutch I would doubt that would be the problem. Those clutches have a tendency to "grow together" instead of getting loose. Of course, that could be the problem, but I'd still look at the belts first. One things for sure, something's causing the blades to stop turning.

Driving slower, and tipping the mower will fix the long stem part. Been there, done that.


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## gman1772

I am not doubting you but are you sure you have Kuhn HD blades on that machine? HD blades are longer than normal because that hats are smaller. A buddy of mine did just that and got similar results to yours when he tried to go fast. As for Kuhn being junk I have used nothing but Kuhn cutters for years and have never had problems. Maybe I'm just lucky.


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## JimG

gman1772 said:


> I am not doubting you but are you sure you have Kuhn HD blades on that machine? HD blades are longer than normal because that hats are smaller. A buddy of mine did just that and got similar results to yours when he tried to go fast. As for Kuhn being junk I have used nothing but Kuhn cutters for years and have never had problems. Maybe I'm just lucky.


 Don't worry about doubting me cause I am definately doing something wrong. I don't know if I'm using Kuhn HD blades or not. I bought my blades at the local John Deere dealer. My machine is a John Deere 265 which I believe is the same as a Kuhn GM700. I bought my blades at my local John Deere dealer. I just asked for a set of blades for my machine. Maybe I should get some blades for a Kuhn HD and compare them to the ones I'm using.


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## mtarrant

I am just east of you in Athens, unfortunately I think a lot of the problem is the cutter bouncing over gopher mounds. Tilting the cutter bar over a little did help a little, so it goes thru rather than over.


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## gman1772

Don't worry about doubting me cause I am definately doing something wrong. I don't know if I'm using Kuhn HD blades or not. I bought my blades at the local John Deere dealer. My machine is a John Deere 265 which I believe is the same as a Kuhn GM700. I bought my blades at my local John Deere dealer. I just asked for a set of blades for my machine. Maybe I should get some blades for a Kuhn HD and compare them to the ones I'm using

Your cutter is a GMD 700 HD Kuhn machine rebranded by JD. It will use a special length blade. I would try using it without the caddy. I use a GMD 600 HD machine right now and have had 0 problems with it for 3 years. The only other thing I can think of that has not been mentioned here is that your tension spring might be improperly adjusted. Does your cutter "pop up" a lot on fireant or gopher mounds? You might have too much tension on that spring.


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## Blue Duck

JimG said:


> Don't worry about doubting me cause I am definately doing something wrong. I don't know if I'm using Kuhn HD blades or not. I bought my blades at the local John Deere dealer. My machine is a John Deere 265 which I believe is the same as a Kuhn GM700. I bought my blades at my local John Deere dealer. I just asked for a set of blades for my machine. Maybe I should get some blades for a Kuhn HD and compare them to the ones I'm using.


If you did not give the JD dealer your serial number you might have the wrong blades. There are two different blades offered, they are different in length. My 275 takes the longer ones and the JD dealer tries to sell me the short ones every time.


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## whitebc

I just mounted my Kuhn 700 on a cutter caddy this year and had the exact same problem you are talking about, I adjusted the cutter bar down at an angle to the ground and let some of the air out of the tires. the tires were so full of air that they would bounce on every little hole. I have cut about 100 acres with it so far and have not had any more problems. Hope this helps you out.

Ben


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