Riding mower leaves grass uncut

[fordmudduk]

I am on my way out to mess with the mower this morning. I do believe the 1inch diff is not correct. It is equal on both sides of the blades. You rotate and its exactly the same on the other side. I am positive it is not a bent blade. As these are new out of the box and the older set I replaced did the exact same thing. The older set were highlift blades while these are mulching blades.

I am going to double check spindles and such....

 

[tommu56]

It might sound crazey are your blades on backwards? I'v seen it once on a friends mower
I'v put the wrong twist in my jd312 and blades ran wrong way my daughter made a couple passes around the yard till I noticed it.

tom

 

[bontai_Joe]

You mentioned that you replaced a spindle a while back after hitting a stump. Possible the sheet metal of the deck shell is bent, causing the spindle to be out of aligment. This can sometimes be fixed with CAREFUL use of a hammer and/or use of washers as shims to relevel the spindle. The fact that when you checked the blade tips at both ends and they were about 1" out of being in the same plane indicates to me that the new spindle is either tilted, or the blade isn't mounted correctly on the star as mentioned above. It's fixable, will just take a little patience and persuasion.

 

[whistlepig]

If it's leaving a strip of grass it can only be these things:

A blade is bent.
A spindle is bent.
The deck is bent.
A pulley is slipping.
A blade bolt is not tight.
A mismatched blade.

That's about everything going on under a mower deck. I have never bent a mower deck. I have bent several spindles and blades though.

 

[zzvyb6]

You should check to see if the blades are all turning the same way. If your belt is mis-routed, then a blade going the wrong way will drill a strip in your lawn. Someone may have also had a belt problem and found one that worked but not in the way it was intended. Oops. If so, then you are gonna need to have a new belt and it will definitely be a different length.

 

[Alan L.]

Sounds to me like the deck got bent when the stump was hit. If the blades are not the same height at the point where they rotate to the middle, its probably because the spindle is not perfectly perpendicular in relation to the deck. It can probably be bent back, or you can use spacing washers on the spindle mounting bolts to align it.

It is very easy to bend this lightweight deck.

 

[fordmudduk]

Ok well I tried a new belt today and no help. I have inspected the pullies and none seem warn. I remeasured the blades at tip to tip in the center and the left vs right is 1 blade thickness 1/4" not 1" as I stated. Not sure where I got the 1 inch from. I did notice today after trying the new belt. The grass left uncut or barely touched is more pronounced in turns. Turning left the left blade seems to leave a 3-4" wide section towards the middle of the deck uncut or slightly touched.

I have taken measurements of the blades to the ground all seem to be inline with the deck adjustment listed in the owners manual.

So I am worn out from working in the garden today, I really didnt give too much effort to the rider. Will look tomorrow.

Corey

 

[Scooby074]

Sure is a weird one.Is there any play in the spindles?

Pics may help.

 

[jhwentworth]

Ok well I tried a new belt today and no help. I have inspected the pullies and none seem warn. I remeasured the blades at tip to tip in the center and the left vs right is 1 blade thickness 1/4" not 1" as I stated. Not sure where I got the 1 inch from. I did notice today after trying the new belt. The grass left uncut or barely touched is more pronounced in turns. Turning left the left blade seems to leave a 3-4" wide section towards the middle of the deck uncut or slightly touched.

I have taken measurements of the blades to the ground all seem to be inline with the deck adjustment listed in the owners manual.

So I am worn out from working in the garden today, I really didnt give too much effort to the rider. Will look tomorrow.

Corey

Just a couple things to check.
Verify that the blades are not upside-down. Most AYP replacement blades are stamped "grass side" to identify the correct position.

Measure the width of the cut made by both blades; it should be very close to 42". Also check the clearance between the blade tips in the horizontal plane.(how far apart are the blades?)

Check the level of the deck by positioning the blades front-to-rear and measuring the ground clearance while on a flat surface. All 4 blade tips should be within ¼".

 

[alchemysa]

The grass left uncut or barely touched is more pronounced in turns. Turning left the left blade seems to leave a 3-4" wide section towards the middle of the deck uncut or slightly touched.

Corey

Thats normal when one blade is set forward of the other (as they are in most mowers). It's designed that way so the cutting paths can overlap without the blades hitting each other. You'll get a bigger uncut line if you turn in the direction of the blade thats set further back. You'll have no line if you cut in the other direction.

Anyway you shouldnt have an uncut strip when you cut in a straight line.

If one blade is longer than the other put at the rear, it might make a difference. Make sure they are they are up the right way.