Mower leaves strip

[Striper]

Hi, I have a 48" Exmark Viking. When going at a higher speed it leaves a strip on the left or right, or at times both. However, when I go slower it cuts great. Would it be that I was going too fast, or is it something wrong with the mower. I have asked a couple mechanics and the dealer near me and they said to check the belt and make sure it is tight enough. I had never checked the belt before and it was very loose and glazed. I ended up purchasing a new belt for my mower but still have the same problem. Would anybody know what would cause it to leave the strip?
Any tips will work. Thanks in advance

 

[exotion]

Ya you need to slow down. Sharp blades and clean deck help to.

 

[Striper]

Yes, I have thought that was the problem I just wanted to make sure there was not a problem with my mower.
I sharpen my blades about every 2 weeks, I cut 11 lawns a week.
I also clean my mower deck quite frequently

 

[exotion]

Yes, I have thought that was the problem I just wanted to make sure there was not a problem with my mower.
I sharpen my blades about every 2 weeks, I cut 11 lawns a week.
I also clean my mower deck quite frequently

Do you bag or mulch or discharge? If bag or discharge high lift blades will help to as it sucks the grass in.

 

[Striper]

I discharge. I also have all high lift blades. At times I have to cut the lawn 2 times because the strip is so bad

 

[exotion]

So if your blades are sharp, deck clean, high lift blades, new and adjusted correctly (I'm assuming. Don't want it to tight or loose) belt. Are your spindles spinning freely and properly greased? Any debris lodged under the engine? Engine speed good? How about drive belt is that to tight? Could be taking energy from the blades. Beyond that there is nothing else

 

[Striper]

Okay. Thanks for the help. I will check and make sure everything that you have said are okay. I always check underneath my mower deck and keep up with maintenance

 

[Striper]

After further looking into the problem, it is looking like it is occurring more when I change the height on my front wheels. The exmark 48" Viking hydrostatic that I have only allows me to make quick adjustments on my front wheels, the rear stays the same. At times customers ask me to cut their lawn lower and that's when I am getting the line(s) of uncut grass.
Does this sound familiar to any of you?

 

[RaptorSD]

Same here when running a high lift blade, I think it folds the grass over prior to being cut more noticeable in taller grass. Not a problem with med-high lift.

 

[Striper]

Ok. Thank you