Combines looked at a 1680 today and have questions

If I'm following u right it sounds like it has an airfoil chaffer. Every combine I've owned ran with an airfoil chaffer (jd 7700 and 7720, mf 750 and 760 and 8780) it makes an excellent sample in wheat and soybeans along with other cerels and canola. (in soybeans you can just about turn the air right to max... my dockage is usually around 0.5-0.75%) We used to use a airfoil chaffer in corn too in our old JD 7700 but then we got tired of the late falls. It worked good but some guys say u loose abit of capacity in corn. These are just my experinces from Manitoba, Ed

When the Power Guide wheel drive is engaged I loose 29% ground speed (Slows from 6.2 to 4.4) If possible drive the machine around the lot to check speed with 4WD engaged then disengaged. With 4WD engaged you operate at lower system pressure, extending the life and running cooler oil temperatures.