Combines 9880 STS same problem in wheat

Has this machine got an adjustable pre-cleanerIJ If it has than close it down to about 10mm. Top seive around 12-16mm, bottom 6mm. Don't rely on the guage on the side of the machine or the corner post display for settings - get in from the side a actually measure the distance, then calibrate the readings on the side indicators etc. Feeder chain on high speed, feed drum in low position, feed accelorator (FAST) in high. I pressume you are running small wire concavesIJ If not get them in. Concave clearance should be about 10-15. Make sure the concave is zeroed and level. Rotor around 750-810, depending on crop conditon, grain moisture and ambient temperature_humidity. Fan around 1100-1250. I don't know if the 9880 has the 60 series fan or the 50 series. This speed is for the 50 series. A 60 series fan is bigger in diameter and doesn't run as fast. You should be able to set this machine to give an excellent sample.

This will be my first time with my STS and was wondering if I need the separator grate coversIJ The local dealership, who has never run small wire concaves in wheat, recommended to put 12 covers on left side and 8 on the right side. Also, are the concave cover plates worth having as wellIJ

you can stop the straw going in the bin in canola by covering the rake on the pre-cleaner this stops the chaff and straw falling straight through. A mate did it and said it works well.

I started off with largewire concaves with cover plates on the middle of each concave and separator plates on left and right etc. etc. You just can't get it to perform to an acceptable capacity, grain sample or grain loss with this setup. I found it made a very large improvement when I put in 2 small wire concaves at the front and took off the remaining rear concave cover, took off most of the grate covers - I am pretty sure you could run with no grate covers at all once you have an adjustable pre-cleaner. This adjustable pre-cleaner is a must for all crops. If you are only doing corn then the fixed pre-cleaner is OK. I even tried a 60 series pre-cleaner in my machine but it made no real differance. Since the fixed pre-cleaner is set at 25mm, it is impossible to keep small bits of straw and unthrashed heads falling through and going around again through the return elevator into the rotor and adding unwanted additional load to the threshing and separating system. So what does everyone doIJ They start putting cover plates on concaves to thresh the crop, then they put cover plates on grates to reduce the trash load on the sieves, then you increase air because the cleaning system is overloaded - you are constantly chasing your tail with an unacceptable result. My advice would be to get an adjustable pre-cleaner fitted from new and put at least 2 small wire concaves in when doing cereals. The pre-cleaner is available from JD.

demonstrated a 9650sts with round bar concaves in wheat 2 years ago, did a terrible job. got a 9750sts last year and put small wire concavesin it for wheat, also 12 cover plates on left side of seperator for wheat, does a supper job, .2 to .5 dock, very clean sample. it would be nice to be able to adjust precleaner in some crops though.we put round bar back in for corn,soys and white beans and take off cover plates. concaves are not as easy to change as JD. people say.

The problem was in the precleaner, it is fixed, meaning opened all the way and there goes thru the load to the sive and it is not able then to clean all the stuf. Covering the precleaner helped a lot. Other problem was with sives not being zeroed. Now it does much better job. Thanks all for help.