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The concaves worked good for us but still not perfect.

 

Had similar problems with one of our 9770's. Turns out we had a bent concave hanger. We replaced the hangers and leveled the concaves which improved our threshing dramatically. In hard red spring wheat it would be nice to have a few more rpm though.

 

But in rice elements and rice concaves, big improvement

 

I never run the concave any closer than 15, then open it 2 or 3 points as the day warms.

The STS combine does a much better job if you open the concave provided
the concaves are levelled.

MS

 

I have the PFP rotor kit/extra narrow concaves and I run the concave between 20 and 25! This is HRS wheat, very little loss out the back and the dockage is around 1.5%.

 

I also run PFP Parts in 9760 but its more than just the concave's! There are 5 steps PFP recommends but due to cost I have only completed 3 and still have close to the same results as my neighbour who has completed all 5. I have installed Rasp Bar Threshing Elements I also run concave #1 & #2 PFP extra narrow and #3 JD narrow I also have a PFP Back Beater Speed Up Kit! The parts I am missing are the Feed Accelerator Beater for more uniform feeding and the Back Beater for more uniform straw spreading (I notice this the most, it is next on the list, mine spreads more out the right no matter how I set the deflectors behind the rear beater???). Oh ya and for those butts (unthreshed heads) there is a 1/2" gap on the right side just above where the concave slides on to the pipe that holds it in place, fill that gap!!!!! I wouldn't be surprised if more than half of your butts are coming in there?

Note: if you switch crop types (small to large) frequently this may not be for you, changing concave's isn't a big deal but I could see it getting very annoying!

So like cnd I also run my concave's at 20-25 with zero filler plates, (get rid of those tine fillers to) feed accelerator in high, rotor maxed, wind maxed, chaffer at +/-15 and sieve at +/-6 and my dockage in Durum is between .4 and .6, loss is minimal and fuel consumption is drastically less then stock deere, in good going I have no problem averaging 1200-1300 bu/hr all day long and with a little more hp it could be better

PFP - Precision Farm Parts
John Deere STS Combine Parts

 

I don't know of any STS owners that set the concave at 5 in hard to thresh red spring wheat. I know some that used to and were always complaining about poor power and dirty sample. Opened up and away we go.

I work with a chap who has a 1200 separator hour 9760 with original Deere
narrrow wire concaves set at 15-20 in hard wheat, covers on the middle concave, 1.5% dockage, all kinds of power.

Unless I've tried something I don't knock it.

MS

 

99% of STS owners in our area run with the concave anywhere from 0 to 6....anything more and it will not thresh. Have you ever dropped your straw to make sure you are actually knocking it all out of the heads?

 

I have never tried that. I couldnt figure out that even with the sieve closed we still got unthrashed heads in the tank. its like we had something not right or broke but couldnt find anything and concaves were level. is it possible that the rotor is not running the speed it says on the screen? In 1 of the same fields my buddies 9770 worked great and i was running the same settings .

 

9650&9750 we run concave at 15 to 18 rotor at 900rpm in wheat i always drop straw to check for thrashing and loss. I made catch pans that i can drop while moving. I run a small wire in the front and large wire in #2&#3 spots. Run fillers in #5&6 where the return is. Dockage on wheat i hauled so far was .4%

 

Do you only run fillers in #5-6? How bout 1,2,3 are you leaving them open?

 

bent hanger ? you mean bar on the right?

 

Agree with Duane, concave at 10-14, rotor max rpm less 50 is about 990.
chaffer 14, sieve 4, less than 1% dock, little loss at 800bu/hr wheat.
Our dealer recommends 10 as the min concave for max capacity and power.
You need to keep rotor full so the grain threshes against it self not augers around the rotor. Works for us.

 

Running the deere small wire we had white caps first year with our 9660. Switched to a Helical concave in first position, small wire second, and usually a small wire in third, sometimes a small wire with every third wire pulled. Pretty well fixed the white caps.

 

Always end up running 3 to 5 on concave and 1000 on rotor to knock wheat out of the heads on a 9870 in heavy straw. Some wheat does trash much easier then others.

 

We put in extra narrow wire concaves in the first 2 and don't use any filler plates.