Mowing Deere 72" mid mount mower cut quality

[BrentB]

Deere 72\" mid mount mower cut quality

Hi,
I have a 4200 Deere with the 72" mid mount mower with turf tires, and have been disappointed with the cut quality. The mower doesn't seem to have enough suction to pull up the grass that the front tires roll over, so after a day or so the lawn has streaks of long grass. The problem is worst on the bluegrass variety that was laid as sod, but is also apparent on the seeded portion of the yard as well.

How satisfied are other owners of this mower?

 

[JackIL]

Re: Deere 72\" mid mount mower cut quality

Brent,

I have had several John Deere and other brands of decks over the years, and none of them has enough "suction to pull the grasss up that the front tires run over." As far as I know, there is no such deck. There are high-lift blades available for most mower decks that can help, but none I am aware of can lift the pushed over grass back up to a vertical or near vertical position.

The effect you describe is most pronounced when mowing taller grass, especially taller grass that is limber and lush. By that I don't mean grass that is 12 inches tall--I mean grass that is, say for example, 6 inches tall and you are trying to cut it to 3 inches. Most turf experts recommend a cutting height in the range of 2 1/2 to 3 inches for bluegrass, but simultaneously state that no more than 1/3 of the length of the grass be cut off for optimum plant health. So if you want a lawn that is 3 inches tall just after cutting, you should mow when the grass is no higher than 4 1/2 inches. Your deck should produce good results if you can stick to this.

Other effects come into play as well. Both front tires push the grass forward, but the direction of travel of the cutting edge of the blade that cuts the left track is opposite that of the blade and track on the right. Thus one of the depressed grass tracks gets cut in the forward direction and the other gets cut with the blade passing opposite to the direction the grass is lying. The latter one will probably get a better cut since the action of the blade is to try to bring the stems back up. I have often observed this effect (left and right tracks have different lengths) when mowing in grass that is too tall.

Another factor to keep in mind is blade sharpness. Sharp blades do the best job of cutting an produce the least amount of trauma to the stems. Still another factor is blade tip speed. The higher the speed the better the cut. Your Operators Manual will indicate the engine RPM that gives rated PTO speed. On a John Deere this is usually wide open throttle or just slightly below. Finally, forward travel speed of the tractor has an effect. You might try slower travel speeds while keeping the PTO speed at the prescribed level.

Hope this gives you some ideas to think about and try.

JackIL

 

[prosperity]

Re: Deere 72\" mid mount mower cut quality

Excellent reply JackIL.
I have just one other thought to add - are the tires loaded on the 4200? The 4200 is a pretty heavy machine, and if the fronts are loaded too, this could help "mash" the grass to a point that the suction can't lift the grass blades properly.

 

[BrentB]

Re: Deere 72\" mid mount mower cut quality

Thanks for the responses. Nope, the tires aren't loaded. I do have the loader on, though. I would guess the tallest the grass gets is 4 inches before I mow it.

In theory I know that ground pressure is virtually the same as tire pressure, and that my tractor with turf tires should not be any worse than a lawn tractor. Can't say that I quite believe that, though.

Wish I could put a front mount deck on it... that would provide all the advantages, wouldn't it?

Brent

 

[tanuke01]

Re: Deere 72\" mid mount mower cut quality

I don't have a 72" but a 60" on a 4300. I have never had the problem you are having. My tires are not loaded but I keep
4-45# weights on the front. I have truf tires. Med lift blades.

The only items I could suggest is Speed ( mowing too fast) and the loader should come off or at least make sure the air pressure is correct for the weight you have on the front wheels. Also the blade must be sharp.

DPR