deck not cutting properly after sharpening blades

[Hondov65]

Switch the center blade with one of the outer and see what happens.

 

[jenkinsph]

As others have mentioned focus on the front roller issue if this lines up with your uncut strip. Make sure the front of the mower is about 1/4" lower than the rear, if it is pitched to far forward the front roller will bend over the grass too much.

Don't think it is a blade length issue as this would leave small strips either side of the middle blade. If the mower cuts well a few inches away from this strip (still inline with the center blade) don't think it is a belt tension issue as this would affect the whole path of the center blade.


Try a spot running the deck at a higher cutting height to see if the problem goes away. If it does the center roller is the likely culprit, what does the grass look like when you drive over it with the mower deck off? Is the stripe evident?

 

[jinman]

The 5" "UNCUT" portion intrigues me. Do you mean it is uncut completely or is it just not cut at the height of the rest? If your center blade belt was slipping, you'd have a 15"-16" swath uncut instead of 5". The only thing I can think of at this point is airflow pressing the grass down, but I realize that is pretty far out there.

 

[SandburRanch]

The center blade is on wrong. Turn it over.:laughing:

 

[meb9796]

ok, was out of town last week, but I tried the deck again yesterday after replacing the mower to deck belt, same results.

To answer some questions, the grass appears to be not cut at all, regardless of what height I put the deck at. I also thought going too fast was the culprit when I first noticed this when my wife was cutting grass, but I've tried going super slow and it doesn't help.

I've swapped out the middle blade with a side blade and got the same results. The middle blade is NOT on upside down (I tried, they won't even go on upside down :laughing:

I've tried cutting at all different lengths (2", 2.5", 3", and 3.5") and I get the same thing. The front roller is several inches off the ground when the deck is lowered for cutting, so don't even think it's touching the grass when I mow. I haven't tried running over the grass with the blades off to see what that does...hmmm

but...something of interest from yesterday, I put the bagger on to at least get some leaves up from the side yard and it even left a 5" path of cut up leaves when I was driving over them. It picked up about 90% of the leaves, but it did leave a noticeable path of leaf particles on the ground. This kinda points to the air flow possibility that a few people have mentioned.

Today I have to swap out the blades on my chipper, then I'm going to measure the deck height and if it's off front to back, then I'll have to figure out how to adjust it. If that doesn't help, I'm going to order some gator blades and hopefully the vacuum they create will help this issue...who knows

I'm 1/2 tempted to spend the 30 minutes and put the grass blades back on my flail mower and go cut the grass that way :thumbsup:

thanks for all the suggestions guys, I'll let you know what happens.

 

[beenthere]

I get less "vacuum" from gator blades than the regular blades.

Hope you find the problem. Something fishy about it. Maybe a baffle or two has been ripped off?

 

[tmajor]

Have you checked, yet, to see if the idler /tensioner pulley works, as it's supposed to? If that spring can't move the pulley on it's pivot, "Things just aren't going to work correctly!"

 

[locknut]

Now I'm really stumped!! I took the blades in to get them sharpened, put them back on, greased up the deck 'again' made sure all the pulleys were turning properly, and replaces the belt, and I still got the 5" path of uncut grass, regardless of speed (crawled and went as fast as I could go with the same results. I have a large front yard with thin grass in some sections and real thick grass in the middle, it the did the same for the entire yard, regardless of type of grass or speed.

I took the deck off 1/2 way thru cutting the yard (was a bit peeved at this point) and checked the entire thing again, and even swapped the center blade with one of the side blades and STILL got the 5" strip.

I still think it has to do with belt tension because the two end pulleys have more contact (i.e. friction) with the belt and the middle pulley has about 1/2 the amount of contact, so seems liable for it to go first if the tension is off. Since I replaced the belt, what about the spring that is on the deck? Should that come off easily?? It takes almost no effort for me to remove/replace it. I think I'm going to stop by the JD dealer and ask to see one of the springs to compare the tension and possibly try new blades, even though I really doubt that is it. While I'm at it, I might as well get a new belt for the mower to the deck too, I did notice a few cracks in that while I was taking the deck off this afternoon.

Thanks again for all the input and I'll keep you posted.

The idler pulley should move freely on its pivot.Sounds to me like it's frozen.With the belt installed and routed properly,removing the the spring should require considerable effort.Sounds to me like the center blade is not coming up to speed and the air flow from the outer blades are overwhelming the air flow from the center blade,thus pushing the grass down in the center of the deck and the center blade is not lifting it up to cut it.

 

[jenkinsph]

The idler pulley should move freely on its pivot.Sounds to me like it's frozen.With the belt installed and routed properly,removing the the spring should require considerable effort.Sounds to me like the center blade is not coming up to speed and the air flow from the outer blades are overwhelming the air flow from the center blade,thus pushing the grass down in the center of the deck and the center blade is not lifting it up to cut it.

This sounds plausible to me, as I have been trying to fathom how you could wind up with a strip that is uncut. I agree that the belt tension issue needs to be addressed before you proceed.

 

[locknut]

This sounds plausible to me, as I have been trying to fathom how you could wind up with a strip that is uncut. I agree that the belt tension issue needs to be addressed before you proceed.

Yep,that spring issue is likely the culprit.If it can be removed with little effort,it's not doing its job.All the decks I've seen probably take 20-50 lbs of force to remove or install.Never worked on a Deere deck though.