Hi,
Well, it's a Gravely so that's a plus.
As with any machine it's age (produced '78 thru '87), maintenance over it's life is key.
The 8171's (all?) came with an Onan CCKA 16.5 which is a powerhouse twin engine. No longer produced, parts can be expensive, but there are many that love this engine and feel it's worth the money to keep it running. That is something to keep in mind when reviewing the tractor's condition.
Other things to look for are: Clutch condition- are they wobbly on the shaft due to neglect or abuse? The splined shafts are a point of wear if not maintained. The clutch pads are replacable.
PTO condition is one of the most important considerations as I hear it is an 8 hour intensive job to replace. Make sure it operates normally.
Steering has some adjustment in it, but again, was it lubed throughout it's life? Excessive wear causes need of replacement parts and can offset a bargain price. Still, unless the machine is totally hammered and rusted out, it's likely worth fixing anything that's wrong.
There are coveted options which should be considered in the purchase: Does it have hydraulics? Optional front or rear PTO kits? Wheel weights or weight rack? Liftable hitch? Some of these items can fetch a pretty penny by themselves.
It's pretty common to find 50" decks with holes. If it's too bad to repair, they do come available quite often.
Sorry for rambling all over the place...I'm sure there are some points I have missed that others will hopefully join in and add.
Oh, the 800's were prone to having a frame crack under your left butt cheek. Not sure if the 8000's had the same issue.
Manuals, sales brochures, and IPLs are available at oldgravelys.net
Good luck!
Tony
