Trouble Shooting Uneven Cut

Discussion in 'Mechanic and Repair' started by Ching-A-Ling, Oct 21, 2012.

  1. Ching-A-Ling

    Ching-A-Ling LawnSite Member
    Posts: 23

    I am getting an uneven cut on my 2007 Dixie Chopper; I grew tired of keeping up with a slow leak in a front tire so I upgraded to the 'never flats'; I've checked the rear pressure and up to spec.

    It seems like the 'lower' cutting blade is the front left (as you are sitting in the seat looking forward); I have never replaced belts; I have adjusted the tension on the two places according to spec. Belts don't look bad, but I have purchased replacements and have them on hand should i need to (just thinking that I'd rather not screw with the belts if there isn't anything wrong).

    Is there anything else that a do it yourselfer should try before I go borrow a trailer to have someone look at it?

    Mower is a residential use and only has 300 hrs on it.

    Thanks in advance for your thoughts.
     
  2. 44DCNF

    44DCNF LawnSite Bronze Member
    Posts: 1,460

    You can't assume that equal pressures on tires will give them the same diameter/height. As tire molds wear the size of the tire changes. You may have two tires on your machine from different molds or production dates, thereby giving you different heights at the same tire pressures.


    There are 2 Methods I use to overcome this:
    1. Grab a level, and a rule taller than your tire. Lay the level across the tread of the tire and level it. Measure from the level to a flat surface you have parked the machine on. Suppose you got 14 inches on that tire and you know it is at the specified pressure. Now do the same for the other sides tire. Level across top of tread sticking out to the side, measure height. It will most likely vary a little. Now add or remove enough air to bring that tire to the same height as the other side. Take note of each tires pressure. Take a paint marker and mark each wheel with the respective air pressure that leads to the same height tires.
    OR:
    2. Take a piece of small coated wire cable or electrical wire (to avoid stretch) long enough to wrap the circumference of your tire and add a few inches to it. Wrap this around the tire and with a marker make a mark where one end meets up with the other end (near the end) of the cable. Now take that cable and wrap the other sides tire and match your one end to the mark you made. Adjust the inflation until that tire has the same circumference as the tire you previously measured. Take note of the air pressure of each tire and mark the wheels with a paint marker accordingly.

    From then on fill your tires according to what you have marked on the rim. One tire may be 15 psi, and the other may be 13 psi or 17 psi to obtain the same height/diameter or circumference. Fairly regulary check against your level and rule or wire cable to verify your findings are accurate.
     
    Last edited: Oct 21, 2012
  3. 44DCNF

    44DCNF LawnSite Bronze Member
    Posts: 1,460

    Once you've got the tire height worked out, and maybe before you make your psi markings on the rims, you can make or obtain blade height of cut guages and measure height of the blade tips. Park on flat surface. Measure blade tip heights while blades are all in like positions. A stacked combination of large nuts taped together will work. This is easier than trying to see under a deck and measure with a rule. Further adjustment of the air pressure may be needed to finally level the blades.
     
  4. Darryl G

    Darryl G LawnSite Fanatic
    Posts: 8,033

    Ummm...the level of the deck is adjustable too. Exmark has a detailed procedure in the manual for mine which involves loosing the hardware and dropping it down on blocks of wood on a level surface.

    But the first thing I would check for is a bent blade.

    I'm not saying tire pressure and circumference aren't important, but a bent blade or your deck needing leveling could be the problem as well. Personally I just set all my tire pressures the same and adjust the deck from that point.
     
  5. Ching-A-Ling

    Ching-A-Ling LawnSite Member
    Posts: 23

  6. 44DCNF

    44DCNF LawnSite Bronze Member
    Posts: 1,460

    I am speaking of the larger drive tires and leveling out the mainframe/engine deck as a starting point. If your drive tires are not inflatable then you are left with leveling the deck regardless of whether the mainframe is level.
     
    Last edited: Oct 21, 2012
  7. Darryl G

    Darryl G LawnSite Fanatic
    Posts: 8,033

    What I do when I want to check my deck level is just measure the distance from the lip of the deck to the floor at the four corners of the deck. Ultimately your cut depends on the elevation at the tips of the blades though. I have had several blades go "concave" on me for no apparent reason other than possible age/use...no known hard strikes.
     
  8. Ching-A-Ling

    Ching-A-Ling LawnSite Member
    Posts: 23

    Shouldn't have underestimated the need for new blades; life is back to normal again. easiest fix of all.
     
  9. Ching-A-Ling

    Ching-A-Ling LawnSite Member
    Posts: 23

    First cut was a champ; Dropped the blades down .25 inches after the first frost and i'm back to the same uneven cut I was getting before the blade change.

    Wondering if i somehow caused the deck to get even when i jacked the mower up to change out blades.

    Anyway, it seems to have the lower cut on the blade closest to the (while looking at the mower, not sitting in the seat) right wheel; I can see the adjustment bolt and chains, but nothing appears to be out of line.

    I also took the 'level' out like you guys suggested and i'm not seeing anything that indicates one side is favored over another.
     
  10. Ching-A-Ling

    Ching-A-Ling LawnSite Member
    Posts: 23

    No other ideas? Will love to see how this troubleshooting (post trailer) goes..... I may jack it up again and see what play there is in the deck to see if something is just not floating to the right position, etc.

    Sorry to keep bmping this back up. But i know you guys will have an answer that will lead me to right place to check.
     

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