Pony cutting strips in the lawn

Greetings all,
I picked up a used Pony, 13WN77KS011, and it all seems to work great, other than the left side of the cut seems to be slightly different. It leaves a strip down the left side. The manual said to check the blade height and adjust. The front was off about an 1/8 inch, but I am not sure that's the problem. I noticed that the Pony doesn't have deck wheels, but I am not sure that would be the solution. Any thoughts on that or about added wheels to the deck?
The guy that owned it before had a very small yard and didn't use it much in the last two years. I got this from the estate sale agent, so he might have been feeding me a load. I feel I need to change the oil and maybe the blades or at the least sharpen them. Is there anything else I need to check urgently or should I just take it in have it checked out?
I know I am asking maybe newbie questions, but you can't learn until you either screw it up or ask someone. And I am tired of screwing it up. :wink:

thanks,

GT

With a machine with unknown maintenance always do everything you can.
Oil and Filter
Air Filter
Remove blower housing and clean
Dump gas and put it in car. Get New gas.
Change Spark plug.
Grease all zerks
Spray lithium grease all pivot points
Clean off top and bottom of deck
Check air pressure in tires.
Check belts.
Get your manual troybilt.com/webapp/wcs/stores/servlet/DisplayOwnersManualList?storeId=10001&catalogId=14102&modelNumber=13WN77KS011&serialNumber=
Hope I remembered it all.

:welcome:

If you want some good help we need a lot better information.
Exactly what do you mean .
Leaves a strip of uncut grass, cuts taller,cuts lower leaves occasional bits uncut ?
If uncut grass where, between the blades on one side of the blades ?