OK, I have the 920 flex head on the 9400.  It has worked great for 20 years.  About all I can ever remember have to ever do is clean the contacts on the dial-a-matic sensing box once or twice to get the float to work right. 

Now when I have the combine set in the dial-a-matic location of 1, 2 or 3 it will float over the gnd just fine as I drive along.  I get to the end and raise the head up a foot or so to turn around and let go of the lift button.  The head drops back down.  It should stay in the spot where I stopped lifting until I give it the command to drop by pushing the drop button once.  If I raise it to full height it will stay most of the time. 

I took the cover off the dial-a-matic sensing box and cleaned out a little dirt and cleaned the contact plate with emery cloth.  I pulled the spring loaded contacts and they are OK. 

The book says to adjust the actuating switch, but that is only for the 6620,7720,8820 combines.  There is a chain length to adjust.  Does this combine have an actuating switch some place I do not know of ?

I see some ware on the inside of the dial-a-matic cover in a circle form.  Do I need a new box cover ? 

I went and messed with the accumulator cylinder valve but it did not change anything. 

Thanks.