Leaves strips when going straight.

my L130 with teh 48" deck was doing the same thing. if i was cutting short grass, it was fine, but cutting more than 1" off grass, or less if the grass was really tall, and i would get 2-3 totally uncut strips of grass roughly 3" wide each. forever i cut with half the deck cutting new grass, half cutting the previously "cut" grass to eliminate this.

i found i had several problems:

1. deck was not only unlevel but torqued back and to the left thus allowing the grass to pass between the blades.

2. bad deck spindle causing the blades to wobble slightly. with the motor OFF, reach under the deck and see if the blades wobble at all. if they do, and the bolts are tight, then the bearings are gone and you should replace the spindles.

3. even after fixing this and putting on new Deere blades i still had this problem to a lesser extent. I put on a set of Gator blades and now it ONLY does it if i am cutting tall thick grass.

I don't know of any 3 blade deck that has timed blades. Sounds to me like your blades may be worn out. They definitely need to overlap, the more the better. When buying new blades, the wider you can get the better at it is the diagonal that counts.

Walt Conner

The blades are brand new. I bought the factory john deere blades with the thought that I would question aftermarket blades if I bought those and still had the problem.

No play at all in the spindles.

"Does it matter how the 3 blades are installed?"

Make sure that you installed all of your blades with the beveled surface on top (toward the underside of your deck).

Please let us know if blade installation was the problem.

-Deerslayer

Yes they're on correct. The mower was doing this with the old blades. I thought maybe someone had put the wrong blades on or just worn out, even though they didn't look that bad.

Here are some other possibilities:

Worn deck belt
Deck idler pulley tensioner is stuck
Bad deck idler pulley tensioner

Please let us know the outcome.

-Deerslayer

The information below is from Cub Cadet's website but should is not brand specific. I believe your problems are #4 and #6.

Why am I leaving an uncut strip of grass with my riding mower?
Question
Why am I leaving an uncut strip of grass with my riding mower?
Answer

It is likely that one, or a combination, of the following five scenarios is resulting in the uncut strips.

1) The wrong size blades have been installed.

2) The blades are installed upside down. *Please make certain that you have the correct blades and they are installed properly.

3) The blade tips are worn. To correct this, replace the blades.

4) Overlapping may be insufficient. The tires push down grass during each pass. If you line up your tires with tire marks from the previous pass, the grass does not get a chance to stand back up during either pass. Overlap more than the width of your tires on subsequent passes. This will allow the blades to draw up the trampled grass from each previous pass and should produce a nicer looking cut.

5) Making sharp right hand turns. Twin-blade mower decks are designed with the discharge on the right side and two side-by-side blades. The side-by-side twin blade decks have the left hand blade positioned slightly forward and in front of the right blade. This provides cutting overlap when traveling in a straight line. As a result, the tractor should mainly operated making primarily left hand turns when cutting. During left turns this cutting overlap is maintained. If turning right when, it is possible to negate this overlap and leave an uncut strip.

6) Improper cutting deck adjustment may produce a vacuum imbalance that, under certain circumstances, could cause the air flow to push outwards from front of the cutting deck. Most of our deck designs are of "free floating" design. Free floating decks should not have the anti-scalp wheels touching the ground when the tractor is positioned on level surface. Free floating decks should be adjusted so that the front deck lip is approximately 1/4"-3/8" lower than the rear lip of the cutting deck. This relationship and adjustment should be maintained throughout the cutting height adjustment range. If the nose of the deck is higher than the rear of the deck improper air flow underneath the deck may result. Improper vacuum underneath the deck can negate the necessary "lift" needed to stand the grass blades erect for even cutting. If the lawn has bare spots, or lacks a healthy lush character, this too can cause vacuum leaks, especially pronounced in the higher cutting settings where the grass blades are further spaced at the tips and vacuum leaks may become more pronounced. Please consult the tractor Operators Manual for specific Deck Leveling and Deck Engagement adjustments pertaining to a specific model tractor.

I agree that #4 may be the problem since the uncut strips occur when going straight.

I'm not sure about #6. A vacuum problem usually results in an uneven cut rather than uncut strips. A side to side leveling problem usually results in one higher strip not two.

-Deerslayer

Interesting...but if the tires were smashing the grass down and leaving 2 strips, I can see overlapping on the next pass and catching the one strip but, in order to catch both I'd only be using 1/3 of the deck.

My test after I would make an adjustment this weekend, was to drive the mower to an uncut part of the yard, engage the blades and mow ~15 ft., get off the mower and look at the path I mowed. Standing behind the mower I would see 2 thin strips left. If you divide the 54 inch deck into thirds, they would be at 1/3 and 2/3's. I need to go back and check to see that the front is lower than the rear. I got really frustated trying to get all the blade tips level, side to side and front to back. I followed the manual on these adjustments and it said to get them within 1/8".

I know this thread is ten years old, but I hope this will provide someone with a bit more information, if not actually help.

I have a John Deere 255 Z-Trak. It leaves a strip about two to three inches wide on the right hand side of the deck, not where the front or back wheels align. When cutting just an inch off the top it is barely visible, but the taller the grass the worse it gets.

I've tried everything above and in addition installed mulching blades hoping it would help with any vacuum problem. They did help a bit, but not enough.

I believe it is a design problem with the deck itself. I found that grass clippings are bunching up to the forward side of the opening at the discharge. When I keep it clean it cuts much better. But even then, not as good as it should.

Anyone else?

having this same problem. LT50 we bought 4 years ago. It has almost always left two uncut strips. taller the grass the worse it gets. new blades, leveling the deck, repainted the underside of the deck, coat the deck with pam, used oil, motorkote, nothing helps. i am going to get some new blades tomorrow, and then i am going to cut the bottom strut from the chute. My dad has a 54 inch cub that does the same thing, just not as bad. he just recently bought an Ariens zeroturn that works like a dream.

I have a RZT L 54" Cub Cadet. I have the same problem if the grass is much over 3" tall. If it's not, then the problem isn't as bad. I've tried everything listed above but still no fix. I believe the problem though is some kind of deck misalignment or possibly the blades are getting bogged down and spinning too slowly to pull the grass up. Since I like to keep my grass height between 2-3", I ALWAYS have this problem and have to mow my yard TWICE every time. It's very annoying. I have been looking into buying an Ariens. We'll see. I'll update if I ever figure it out for sure.

My JD L110 also!

Lol. Yeah. Ours too. Which is why we got the Cub Cadet!

Same here! I have a John Deere z425, have checked all these things and nothing helps. So frustrated

I have a question I got a Husqvarna 24 horse 48 inch cut takes three blades it leaves strips where the two blades meet the middle one and they are new blades from Husqvarna

I have the same problem and I've been experimenting a lot in the last few weeks. Here's what I've find out so far... The mower leaves a lot less uncut grass if I keep the mower chute guard pulled up. It was getting clogged up too quickly and slowing my blades down. If I slow my speed way down, it cuts the grass perfectly. But that is very annoying. If I wait to cut the grass in the afternoon, it cuts much better than in the morning when it's still a little wet from dew. So, if I keep the guard up, slow way down, and wait until the afternoon to mow, then my mower FINALLY mows the grass really, really well. I can live with that I guess although I never had to do all that when I first got it. I hope this helps you in some way!

Yes I bought an older rider yr4500 sears 2006 54” wide 26 kohler. Same thing a 1” wide strip at the intersection of the three blades. Last weekend down to Husqvarna dealer new straight blades, I had aftermarket blades in with a 1/4” drop from spindle to blade tips. Other problems prevented me from mowing the week before so had about 8” of height to mow, worked perfectly. I did have the deck repaired in front and then reattached but left the front down lower. Mowed perfectly.

FINALLY!!

Who knew mower deck geometry was so complicated!

Is this thread still open for discussion ? i have a

husqvarna 5424 with the same problem leaving an uncut strip. I belive the problem is in the design of the deck. when the deck was stamped out the holes the spendles fit in are not the same distance apart. In other words the distance from the left spendle to center spendle is wider than the distance from right spendle to center spendle . At least on my mower it is . if thats true on your mower there is no fix .

Sure wish i would hsve read up on this mower, i got it used and i see why they switched to a diffrent brand, this deck cost me three monthly customers, terrible cutting mower. stripes every yard. no matter what kind of grass, ive spent more money trying to figure out issues than its worth. never buying a ”Deere” again.

There are thousands of JD mowers out there working fine, this may be a bum design but don't trash the whole brand. Not that I'm a fanboy or anything, but I have 2015 D125 that works fine even though it's a 'big box store' type of JD.

I wondered if it is possible to get a center blade that's just slightly longer? Not long enough to hit the other blades but maybe it would cover the gap?

Interesting that it happens more on right turns - never thought about that. I happen to mow in a spiral so the clippings are evenly distributed, and I'm always turning left when I do that. Maybe that's why I never had this problem. Or my D125 just isn't one of the problem mowers.

Most decks perform best when the mower blades are set parallel to each other. Blades can get misaligned when the user sharpens or replaces blades and does not realize that blade orientation matters when reinstalling the blades. Blades can also get misaligned after striking an object. Symptoms of bad blade orientation include uncut strips, clogged shutes, and excessive clipping buildup under the deck.

Had to read that twice but I think you mean that the blades are aligned as two parallel lines (when looking from top or bottom). I always wondered about that with mower decks. As soon as anything slips or you replace a belt, the orientation can be just about anything unless you set it where you want it. I'm going to make sure my mowers have parallel blades from now on.

You understand what I meant. Another way to say the same thing is that all blades should be either verticle or horizontal. The reason that this is important is that each blade creates turbulence which at times bends the grass from vertical while creating airflow that moves the grass toward and then out the shoot. If the grass bends the wrong way, an uncut strip may be left and/or the shoot clogs.

toxcrusadr, I reread your post and I noticed that you added: "when looking from top or bottom". That also is correct. Obviously, all of the blades should be in the same plane (the same distance from the ground). When they are not, uneven wide strips will result. If a deck was bent and then straightened, blades may no longer be in the same plane. If the blades are parallel (looking from front to back) but at different heights from the ground, the problem can be corrected with shims between the blades and mandrels.

I have a 1973 JD 110. My deck has 3 blades. When I mow, there is a THIN line right in the middle of the deck. Maybe 1 or 2 grass stems wide. Think alfalfa's hair! haha I think I found the issue, the tensioner spring in the front was SHOT! My great grandpa bought this new, and is all original, minus rebuilding the transmission. So my thoughts are that the belt was not tight enough. This happened right after I had sharpened and balanced the blades, and placed them like -_- so they are all parallel. I was concerned the motor needed a rebuild(plus a new muffler) but it is a BOSS with the snow blower attachment and tiller attachment!!!!! Once my new yard grass grows, i'll be able to mow again and see how it does. I'm also installing mulching blades, maybe that will help?

Mower decks cut best when the engine is run at full throttle. If your weak tensioner caused belt slippage and loss of blade speed, an uncut strip could result.

It was actually kind of silly for me to say 'when looking from top or bottom' because if they're parallel, they're parallel no matter where you look at them from. :-]

The whole thing about creating turbulence that bends the grass in a certain direction is an 'aha' moment for me.

@Rich my father in law has an old 110, it's a horse. He's older (has been for awhile now!) and doesn't do his own leaves or snow anymore. Several years back I went to visit and there was that beautifully built snow blower attachment and the snow blade for the 110, sitting in the driveway. He had decided to scrap them because "no one does their own work anymore". Well maybe YOU don't! I said. But it was too late, the nephew had already taken out all the nuts and bolts to reuse, and I was 300 miles from home in a Honda sedan. They went to the scrapyard. I was hoping to one day inherit the 110 with all its attachments. Bummer.

I reread my earlier comment and noticed that I spelled "shute" incorrectly...oops!

Also, I noticed that I commented on this topic several times 14 years ago. I believe the forum was a Usenet Newsgroup then...Houzz must have purchased its contents.

I have a 1995 Wheel Horse 312-8 that I purchased used about 15 years ago. I rebuilt the mower deck: new pullies, belts, spindle assemblies, blades and, elevation wheels. Also, I rebuilt the steering: new steering gear, tie rods, bearings, spindles, front wheels (went to 8 inch since I was replacing the spindles anyway, the 8 inch spindles have less drop so the tractor stays level with the larger wheels), and tires. I bought new wheels and Ag tires for the rear, too. All I've done to the Kohler engine is replace the fuel pump, fuel line, and add a fuel filter which it didn't have from the factory. She's still running like a champ.

The JD 110 is a sweet machine. Too bad the attachments were scrapped. As they say, "One man's junk is another man's treasure".

The 110 has a solid engine block of a shockingly large size for a small machine. The pulleys are THICK steel. It's just a tank.

That Wheel Horse looks like a sweet machine. The horizontal main shaft and angled pulley up front for the super long mower deck belt reminds me of the first tractor I owned, a '72 Sears ST-16. I think the deck belt was 99" long. I wish I still had that tractor, it was a beast.

Did this ever get solved? I have a 2019 Ariens IKON -X 42 and the problem is severe! I tried over the last year all that was suggested here. Gator G6 Blades, Leveled deck. I believe it is blade speed although I know people have tried larger drive pulleys or small blade pulleys with mixed results. At one time I had read that Ariens had a kit for the 52 inch to add another pulley and use a longer belt to solve the problem but nothing for the 42 inch. I tied their tech support but they were useless.

If you have a self leveling deck and are cutting along a slope the deck will tend to stay level; but because of the slope the high side of the deck will always be on the downhill side of the deck. Each pass will leave an uneven cut at the edge of the deck.

I have a John Deere L130 42" double blade deck that in leaving a 2" path of uncut grass when going straight on level ground. I'm going to check it out using your helpful tips and l will let you all know. Thanks for the help.

Regarding John D's comment two posts up: I had someone explain that to me recently and I had not considered it before.

Basically what they said is that the decks on riding mowers are usually pushed to the left for two reasons. One, so the deck extends past the wheels on that side and you can get close to borders that way. Two, because the chute or bagger attachment extends out on the right side.

As a result, the center of the deck (center of the blade array) is not at the center of the mower.

So, when you are on a slope, particularly going around a turn on a slope, you get weird results. For example, mowing around a tree that has a bit of a hump around it from the roots pushing up the ground.

Obviously this is an inherent problem with where the deck is located and isn't something you can fix with a kit. Designers know about it of course and try to compensate. Whether a problem with any specific mower is related to this or something else is by no means certain.