721d seems underpowered at times

GHdiesel6

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I have a 2000 721d with a 61" deck and more times then most I have to almost slow down to a crawl to get through grass that my JD rider would cut right through...I always sharpen the blades and mower is up to date on services and has around 1700 hrs on it..I don't know if it has to do with the older style deck or not but I thought that with a 21hp diesel motor it would pull through anything...anyone else have this problem? or have any suggestions?
 

MBDiagMan

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If it's tall and wet, assuming that the blades are sharp, it's a matter of volume in the deck. My Bad Boy 26HP, 48" deck is adequately powered to go through tall, damp grass and discharge it without bogging down, so I'm spoiled. My 61" deck, GH 725 gas, which is probably equal to the actual power of your 21HP diesel, does the same thing in tall damp grass. It's not overpowered like my Bad Boy, so I just slow down and deal with it.

What horsepower and deck size was your JD?

Make sure there is no build up under the deck.
Larry
 

GHdiesel6

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My JD was the 345 18hp liquid cooled with a 48" deck.
 

edporch

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I know this is not a recent thread, but my recent experience may be relevant to this.

Check which type of blades are on your mower.

I have a 27hp with a 61" deck and was having trouble with it bogging down.

I found that it had the "Medium Lift" blades on it, and the clippings weren't being thrown out fast enough to keep up.
Hence, I had to go SLOW.

I switched to the "High-Lift Notched" Blades, and it's like a whole new mower!
It doesn't bog down now unless the grass is tall and thick.
It REALLY throws the clippings out and the buildup under the deck both in amount and how fast it builds up has been GREATLY reduced.

Here's a link to a .pdf that shows the different blade types.

http://www.arkansas-ope.com/GRASSHOPPER_BLADE_CHART.pdf
 
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