Have a Cox Stockman ride-on lawnmower that wont cut. Just added 2 new blades (using 4 high lift blades) and still have to go over 100mm grass 3, 4 or more times to cut it down.

It could be two reasons
1: the blade is not sharp enough to cut
2: the bade is set higher than the grass

check that the blades were put on correctly and the sharp side is in the right position . if not then the blades are trying to cut the grass on the back side un sharpened side.

Park mower on a level flat surface ( a concrete garage floor is ideal ) lift deck up until you can put a piece of a 2x4 flat underneath the deck and lower deck until it just contacts the 2x4. loosen adjustment nuts or turnbuckles and adjust until the deck just starts to clear the 2x4. this should level your deck. Now , lift the deck and remove the 2x4. put blade height lever on a known cut length and with a tape measure, measure the tips of the blades from the floor to the blade tip...they should all be the same within 1/8 of an inch...if not then you either have a bent blade, bent spindle shaft, or spindle bolts are loose or misaligned. Your deck could be warped too...depending on how hard a lick it took...good luck !!! ;-D

The following steps will make any riding mower cut evenly.
1. The rear tires must be the same diameter i.e. same tread type and the same tire pressure (check it before each mowing).
2. Level the deck following the instructions in the manual and recheck it occasionally
3. Make sure the blade(s) are not damaged and kept sharp, rounded blades tear instead of cut.
4. Make sure the deck and its attachment points are not bent or damaged.
5. Drive at a slow walking speed with the engine at cutting speed.
6. Over lap rows in amounts sufficient to lift and cut the tire tracks from the previous pass.
7. Cut the grass at intervals that ensures you never have cut more than 1/3rd the total length of the grass.
8. Make sure the underside of the deck is clean.
9. Use a blade style that matches the type of grass you most often mow.

My 10 steps to ensure even cutting for any riding mower.
1. The rear tires must be the same diameter i.e. same tread type and the same amount of pressure
2. Level the deck following the instructions in the manual
3. Make sure the blades are not damaged or bent.
4. Make sure the deck nor its attachments are bent
5. keep the blades sharp and don't drive too fast when mowing.
6. Over lap rows about 20%
7. Cut the grass at intervals that ensures you never cut more than 1/3rd the total length of the grass.
9. Make sure the underside of the deck is free from chunks of clippings.
10. Use a blade with higher lift, yes you have to match the blades to the type of grass you cut most often, (commercial mowers use a universal blade and high speed decks).

When using a bagger, you need correct blades on mower or Worn blades will cause the deck not to get the vacuum needed for the bagger to pickup.

1-----------tire pressure? 14 front 10 rear
start with a level mower on a level surface
2------------deck level side to side?
3------------deck level front to back? (front can be 3/8 lower than back)
4-----------deck hangers bent or hung up?
5------------blades even when pointing at each other? no more than 1/8 high or low
6------------blades dull or upside down? turned up ends go towards deck
7---------------incorrect blades for mower?
8------------deck lifting mechanism should pick up deck evenly and drop evenly?
9-----------under the deck need cleaning because it is packed with grass?

A regular blade has a straight cutting edge, a mulching blade is bent to have a high and low cutting edge. Even if you have a mulching blade on, if the grass is too high or wet or you're cutting too low, it won't do a good job and may require a second pass.Raising your cutting height can help. Hope this helps. Dwain

Hello monica_skinn:

If the Underside of the Deck is Clean and the Blades are Tightened Properly, then the Problem is Caused by the Blade Lifts being Worn or the Blades are Not a High Lift (Bagger Blade) Blades.
A Bagger Blade has a Very High Lift Ear on the Backside of the Blade Across from the Cutting Edge. This Extra Lift is What Gives the Extra Lift and Throw (by increasing air Flow under the Mower) the Grass gets to be Bagged.
Please, Do Not Hesitate, If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance.
Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Be Safe and Be Happy. Thanks.

Good Luck

Respectfully

jbridger (John)