Prolific Poster Award
Join Date: Sep 2004
Location: Coventry, CT, USA
At this point they are all older. A few years plus or minus wouldn't be an issue depending on the bike. If you're going with the older faring, the 4S is a great bike with some nice bolt on parts. Aluminum swing arm, Ohlins shock, 5 spoke rims and the newer ECU with the 996 engine being the primary upgrade. The 4V 996 engine is very nice in this chassis. 2003 likely being the better year, a few of the 2002s had main bearing failures, but I don't think was chronic. If you like the newer style fairing better, you can still get a 4S but the 3 is probably easier to find. The 3S had the same bolt on parts as the 4S, but no change in the engine.
Find the body style you prefer and choose a bike that looks like it has been cared for. Of the two you list, sight unseen, I'd probably go with the 4S if it was clean. I like the look better. The rounded headlight faring looks more "early Ducati" to me.
The maintenance is the same. They all need to come apart for a major service every 6K miles. Some will argue the 3V is easier to maintain. I don't think having to slide a feeler gauge in to two less valves qualifies as easier maintenance... You still have to get to the valves. Fairings on the newer bike are easier to take off, but not dramatically. You don't need to pull the headlight faring to get the sides off. The older bike can be modified to do the same if you choose.
4V flaking rockers. Yes, it happens. Not a big deal in the newer 4Vs. Rockers were improved. Find a few spares on eBay and keep them in your tool box. No problems. 3V had an issue with valve guides, but I'm not sure what years.
Dan. "Painfully mistaking my big talk for the truth" Samantha Fish.
2003 ST4s (The Truck)
1995 916 (Junk Yard Dog)