Second attempt here wrote out a spiel and lost the lot so here goes.
Firstly welcome to the forum.
2007 and 2007.5 well a few things mainly the 2007 and before had issues with the ECU and Stator, the ECU can cause problems where when cold the bike wont idle, so if you find one and its cold and you have to hold the throttle on to get her to run then walk away it could be an ECU issue. Also if its an early bike then get a multimeter across the battery and get the bike upto 4K revs and see that the charge is 14.5v approx, below 13v and its not good could be a stator on the way out. Newer models so 2007.5 dont have this issue as Aprilia sorted these stators out.
Other things to look for is make sure no little mark on the frame down beside the rear brake lever, these bikes (American not as much) tend to easily fall over i know i have done it before. Anyway when they go over they can knock the brake lever into the frame causing the bike to be written off not good.
Oil level, its a dry sump so oil can only be checked after the bike has been out for a blast and taken upto temp and then left to stand for around 10mins.
Valve clearances see that the service history shows these as being checked every 12K
ECU if its running aftermarket cans then it should have the Map2 upgrade, there will be something in the wallet to show this.
Rear brake, make sure this works they have a tendency to be rubbish due to where the reservoir is located.
Connectors, if buying from a garage make sure the connectors have been cleaned up especially down under the tank on the left hand side again i have experience and think this can be a bit of a water trap resulting in corrosion on the connectors and thus bike wont run and cuts out. If however its doing it then its an easy fix and you could maybe knock some money off.
Misting clocks condensation can get in and cause the dash to steam up, i had this on a previous bike and in the end after pulling them apart and trying all sorts i sorted it with a small pin and melting a air hole in them worked a treat.
Other than that its just the usual bike things to check, condition service history marks dings.
Great bikes and if you buy one you will love it, they become rather obsessive owners of the Tuono.
Hope you get one..
