Mower leaving lines advice

m8man

Moderator
Cut a ton of grass here, maybe 10 acres. Lately my mower been leaving lines, thought it was usual blade issues so I sharpened them, no go still sucked. Bought new JD blades installed them same result, I have 3 blades and it leaves 2 strips, sort of a line between each blade. Checked deck level and seems ok. Any thoughts? I almost wonder if blades are to short idk.
 

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euphoric1

Well-known member
did you measure the blades to see if they are correct? how did you measure deck level? when you rotate the blades the tip should come pretty close to the one next to it, from the looks of it I would say either blades are too short, not to ask stupid question but do you have the sail of the blade up in the deck? meaning blades arent on upside down? those are pretty extreme mowhawks, when you rotate the blade tip to the one next to it are they at the same height? I would start with having wrong blades possibly, then I would compare height of blades to the ones next to them. That is definitely not a "level" or "pitch" issue. and make sure when you level the deck you are not measuring off the pan, measure off blade tips. and you want 1/4 to 3/8 pitch also front to back as well... front of deck being lower than the back. level should only be side to side, not front to back. I would start with the blades. did you possibly hit something and tweak the deck where spindle sits, thats where I say make sure the blade tips are at same height as one next to them, have had to take the persuasion mallet to some decks through the years at my shop.
 
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m8man

Moderator
did you measure the blades to see if they are correct? how did you measure deck level? when you rotate the blades the tip should come pretty close to the one next to it, from the looks of it I would say either blades are too short, not to ask stupid question but do you have the sail of the blade up in the deck? meaning blades arent on upside down? those are pretty extreme mowhawks, when you rotate the blade tip to the one next to it are they at the same height? I would start with having wrong blades possibly, then I would compare height of blades to the ones next to them. That is definitely not a "level" or "pitch" issue. and make sure when you level the deck you are not measuring off the pan, measure off blade tips. and you want 1/4 to 3/8 pitch also front to back as well... front of deck being lower than the back. level should only be side to side, not front to back. I would start with the blades. did you possibly hit something and tweak the deck where spindle sits, thats where I say make sure the blade tips are at same height as one next to them, have had to take the persuasion mallet to some decks through the years at my shop.
I didn’t measure the blades just went to my dealer and said I needed new blades for my mower, gave em the model and cutting width.

ticks me off, but gotta figure this out. 4~5 hours to cut my place w a 62” zero turn and don’t wannna do it twice
 

gary_in_neenah

Super Moderator
Staff member
Wondering if those stripes line up with your rear wheels/tires? I'd also actually measure the grass with a tape or ruler. Is there a difference in height or just the appearance? Lastly, when did this begin? After you made a change in settings, blades, etc.

For what it's worth.... l've seen worse lawns. It's green and it's growing! That's half the battle right there!
 

wiharley02

Active member
euphoric pretty much hit everything to check! My first thought before reading his post was bent arbor/spindle or as he said bent deck in the spindle area. I think you're going to have to get on nice flat concrete and get underneath and take measurements blade tips down to concrete, with the blades in multiple positions in their rotation, mower off of course!!!!!!
 

euphoric1

Well-known member
I didn’t measure the blades just went to my dealer and said I needed new blades for my mower, gave em the model and cutting width.

ticks me off, but gotta figure this out. 4~5 hours to cut my place w a 62” zero turn and don’t wannna do it twice
I'm still betting wrong blades or sprung deck, when you get it straightened out just keep in mind when leveling, do not measure off deck pan and level only applies to side to side, for a deck to cut well you need pitch and I would favor the higher end of pitch from front to back 3/8"
 

mezz

Well-known member
I Googled "zero turn mower cut leaving strips", you should check it out. Brian is pretty spot on with his diagnosis. Sometimes it's better to let the dealer inspect, adjust & do annual maintenance. They do pick up & deliver too.
 

euphoric1

Well-known member
I Googled "zero turn mower cut leaving strips", you should check it out. Brian is pretty spot on with his diagnosis. Sometimes it's better to let the dealer inspect, adjust & do annual maintenance. They do pick up & deliver too.
30 years of doing this poop LOL!!
 

m8man

Moderator
I Googled "zero turn mower cut leaving strips", you should check it out. Brian is pretty spot on with his diagnosis. Sometimes it's better to let the dealer inspect, adjust & do annual maintenance. They do pick up & deliver too.
To be honest, I wish they’d pick it up but I don’t have 6 months. Service is the issue, i usually go to “ another place”. I will mess w it some more but may end up buying a new one in the spring. I cut a ton and have about 250 hours on it in 3 years. Love the mower but strips drive me nuts, I like fairway vibes
 

euphoric1

Well-known member
To be honest, I wish they’d pick it up but I don’t have 6 months. Service is the issue, i usually go to “ another place”. I will mess w it some more but may end up buying a new one in the spring. I cut a ton and have about 250 hours on it in 3 years. Love the mower but strips drive me nuts, I like fairway vibes
250 hours is nothing on a mower, not even remotely close, I have customers with over 5000 hours on machines that are 8 years old and still going strong. Where are you located? this year has been a relentless year as far as grass growing, not to mention we are a dying breed and difficult to find people who will or want to work. quality of cut issues are very easy to identify and resolve, just need what and how to look at it.
 

m8man

Moderator
Wondering if those stripes line up with your rear wheels/tires? I'd also actually measure the grass with a tape or ruler. Is there a difference in height or just the appearance? Lastly, when did this begin? After you made a change in settings, blades, etc.

For what it's worth.... l've seen worse lawns. It's green and it's growing! That's half the battle right there!
I’ve had a few sets of blades over the last couple of years and when they get dull I usually get new one and get an oil change. Usually fixes the issue but now that I think of it I have hit a couple tree roots pretty hard so I’m gonna scope it out more on Saturday
 

m8man

Moderator
250 hours is nothing on a mower, not even remotely close, I have customers with over 5000 hours on machines that are 8 years old and still going strong. Where are you located? this year has been a relentless year as far as grass growing, not to mention we are a dying breed and difficult to find people who will or want to work. quality of cut issues are very easy to identify and resolve, just need what and how to look at it

250 hours is nothing on a mower, not even remotely close, I have customers with over 5000 hours on machines that are 8 years old and still going strong. Where are you located? this year has been a relentless year as far as grass growing, not to mention we are a dying breed and difficult to find people who will or want to work. quality of cut issues are very easy to identify and resolve, just need what and how to look at it.
Located in the Keweenaw,
 

jr37

Well-known member
I've had a John Deere Z425 for about 9 years now. It has always left lines in the lawn,from new. I'm diligent about maintenance. The deck gets cleaned after every mow, up on car ramps and scraped clean. Great machine, but not great at leaving a perfect lawn. Early this summer it developed a pretty good leak on the left side transmission. Without time to fix over the summer, I bought a new mower. Fixing the John Deere will be a winter project, when I have more time. I bought a similar size Toro . Only difference is a little bigger engine and a fab deck, instead of stamped on the JD. The Toro does a much better job with actually mowing the lawn. No stripes anywhere. I think the JD machine is better as a whole, but not if you want a perfect lawn. Still trying to get it to where I like it. But, for now, the Toro way out performs the JD with leaving a well manicured lawn.
 

katden4

Active member
Have you made any changes prior to noticing this. If it wasn’t doing it in the past, something has changed. Have you tried a slower ground speed. i have seen mohawking as I call it, when cutting grass either wet, or tall with too fast of ground speed.
 

favoritos

Well-known member
I'm with @katden4 , on the slower ground speed. It's worth verifying that your blade speed vs ground is enough before going nuts on mechanical diagnosis.
One thing I've noticed with many newer mowers is the slower blade speed. I'm not sure if Deere went that route? Their older stuff had those blades a flyin.

BTW, I often hear people mention that they never sharpen the blades. Talking with a neighbor recently, he said he's never sharpened blades his whole life. He just buys new every few seasons. (The cut shows)
I'm in the opposite camp. I keep a spare set of sharp blades on hand and swap during a cut if things look frazzled.

Ten acres is a lot to mow with a blade mower. I bet a bunch of that is some pretty wonky growth. If you have a tractor, throw a brush mower on back for the wonky areas and use the ZTR with good blades to do a fine finish where it matters.
 
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