mower leaves uncut grass

[wdwurker]

My HM722 finish mower tends to leave a path of "partially" cut grass down the middle of the mower. I have put new Hi-Lift blades on it and it still does it. Grant you, it's mostly in High Range on the 4200, but why would the two outside blades cut fine and the middle be sub-par.

Any thoughts would be appreciated.

 

[MossRoad]

The middle blade may not be spinning. The spindle could be messed up, etc... set the deck on a flat surface, like a garage floor, and look under it with a flashlight (not while its running, of course! :laughing and see if the blades appear level.

Raise it up and support it, then give each blade a spin. See if they all turn together.

Hold one of the outside blades with a rag or heavy glove and try to turn the center blade. See if it spins while the outer ones are blocked. If it does, investigate why.

That's all I got. :confused3:

 

[Raw Dodge]

Are any of your baffles damaged,or partially missing? Check that out,also I've seen the spindle shaft splines strip out the pulley and the pulley will simply spin loosely on the spindle..finally make sure your deck pitch is correct,you want the front of the deck to be slightly lower than the rear about 1/8-1/4" at the blade tips when the blade tips are arranged front to rear.

 

[wdwurker]

I don't recall seeing any information on the "set-up" of the blades when replacing them. What I mean is should they all be lined up paralel to each other or should they all be 45degrees from the one next to it?

I have checked the spindles (short of removing them) everything seems to be in order.

If I can figure out how to post a photo, I have one where the sun was casting just the right shadow to highlight my problem.

 

[4570Man]

It might be low tip speed. I was mowing crab grass that was starting to go dormant and my belly mower was delivering a poor cut. It has worked fine all summer on green grass. I hooked up the finish mower which has a tip speed of 26,000 FPM and finished mowing with it. The cut quality was much better.

 

[Creamer]

Not sure how your deck is set up but blade speed is the most obvious issue. Are they all driven with one belt or is the center belt a little loose? Or something else like MossRoad suggested. The other thing I have seen is mowing height and cut material. Depending on the layout of the deck and the amount of material going through the material can lay the grass down especially if you are mowing high. This can make one one blade cut differently than another. this is especially true in the fall when the grass tends to want to lay down more than earlier int he year.

Raw Dodge - My mower likes the front up a little and that is the recommended setting in the book. I think part of that is because the clippings travel along the front of the deck. Maybe this varies with mowers? I never really paid much attention to this other than how mine was supposed to be setup.

 

[CCWKen]

My Woods deck on the ZTR used to do that occasionally (along with flipping and breaking belts). Most notable in higher grass. It ended up being slipping belts. I had to adjust the tension springs on the idler pulleys. They should be pretty tight with a little deflection with hard finger pressure. Your manual should give a spec for the belt deflection.

 

[murphy1244]

Maybe middle blade upside-down?

 

[Raw Dodge]

Maybe middle blade upside-down?

Have you ever installed any mower blade upside down? You would know instantly, that center blade would be scalping like crazy as the lift sail would now b sticking down about 2 inches below the height of cut..don't ask me how I know this...

 

[murphy1244]

Have you ever installed any mower blade upside down? You would know instantly, that center blade would be scalping like crazy as the lift sail would now b sticking down about 2 inches below the height of cut..don't ask me how I know this...

No but I'm out of idea's on his problem.