JD 7700 Corn head

[Allen Rasmussen]

Were looking for a corn head for a JD 7700. should we be looking for a 4 row 30" or an 8 row 30" john deere corn head. We have an 8 row planter. Thanks

 

[Mike Aylward]

Allen, the 7700 combine is too wide to allow a 4-row 30" corn head. If you want to run the same as your planter you will be locked into an 8-row, which was recommended for a 7700 but is a lot of corn head for it. Mike

 

[NutsaboutCombines]

The Model 7700 does just fine with an 8 row head, Mike. The corn itself now doubles the former volume, so the combine only needs to be ran slower.

 

[Moline_guy]

Neighbor runs a 6 row head on his combine, he has an 8 row planter, takes 6 rows opening the field and 4 rows when he goes back and forth to keep in time with the planter. Sometimes the 6 row heads are considerably cheaper than 8rows. I run a 4 row on my 7700 but I still have wide rows. Nice thing about only taking 4 rows is you don't have to have a grain cart following you around in good corn and a fairly long field.

 

[Heat Houser]

My 40 series corn head operator's manual says the 7700 can be equipped with: 444, 543, 546,642,643,644,645,842, and 843 heads.

For the 843 head, recommended ballast is: W/straw chopper, no fluid in tires...install inside wheel wts, outside wheel wts, auxillary wt and a bundle of 9 T weights. W/O straw chopper, not recommended.
If you fill the 11.00-16 tires with fluid, the straw chopper can be removed from the above.

One of the photos in the front of the manual shows a High Tin 843 mounted on a ('75?) Turbo 7700 with the rotary screen....looks impressive.

 

[Mike Aylward]

Yes, it has been done. You won't set any land speed records in good corn but it can and has been done. A 6-row head is a lot more of a balanced size for a 7700. Mike

 

[NutsaboutCombines]

Back in the day, when corn yields were less, you rarely saw many 7700"s with less than 8 row headers.

 

[jddriver]

Mike I run a 643 on my 6600 no probs.I dont see how you could fill the seperator without driving really fast.Lots of 77's ran a lot of acres with a 843

 

[Mike Aylward]

Not around here. Most 7700's were sold around here with 6-row heads. I used to have a 7720 and 6 rows seemed just right. An 8-row head, while very doable, would not have gained bushels per day. Mike

 

[jddriver]

In 200 bpa corn I run about 3mph and the head throws no ears out.This is with a 6600sh and a 643.

 

[Heat Houser]

You are correct, you would not gain bushels per day as the 7700 with a six row head would be limited by the seperator capacity if the corn was standing and you could drive fast enough.

With a 4 row wide, you usually couldn't drive fast enough to maximize the seperator as you were limited by how fast the head could pull the stalks through.

Allen,
With an 8 row, you will drive slower due to seperator capacity. You may gain a slight advantage over the 6 row since you will be turning fewer times on the ends.

Here in my corner of the world, the 6 row head was more popular due to the progression in planter sizes. Most farmers went from 2 row to 4 row to 6 row narrow. Most then jumped to 12 row planters as the 6 row head was still a match. The other problem with going to 8 rows, the early planters did not fold which made transport and field gates a problem.

The 7700 will handle the 843 head. You will be driving slower due to seperator capacity but your bushels harvested per day will be the same, or very close, to a 6 row.