|Replacing 4v Cam Belts
It's generally pretty easy to do. If you haven't already gotten a service manual, I'd suggest that you get one.
You can do it with the engine in the frame, but you must support the front of the engine, loosen the front sub-frame and swing it up and out-of-the-way. Of course, various wire-ties and connections must be removed, too. This also means that the steering damper and fuel tank have to be removed.
Make sure you're at TDC combustion (I can't remember which side to do first) for the first belt. Loosen the three idle adjuster bolts in the correct order. One of them has a locknut on the back(remove that first). Carefully mark the belt with paint and/or count the number of teeth between marks on the driven side. Loosen adjuster and slide belt out. Turn over engine until the other side is TDC combustion and repeat above procedure. You may have to "work" the back belt to get it out.
You should be TDC combustion for the back belt. Install the new back belt (you may have to crank the new belt onto its pulley, but don't damage it). Verify the correct number of teeth on the driven side. Generate the correct snugging torque on the adjuster. At a minimum, you can check for appropriate tightness by squeezing the belt by hand and sliding a 5mm Allen between the belt and the idler pulley, or by twisting the belt 90 degrees on the slack side. Torque down the adjuster in the correct fashion.
Rotate the engine to TDC combustion for the other cylinder and repeat. As a check of the timing (assuming no one has messed with the factory settings) you should be able to see the timing ridges on the front cover line up with the punched dimple-marks on the pulleys.
Be absolutely certain of the timing between the crank and cams before you rotate the engine at any point in this procedure!!!
It's really easy, just be sure to count the teeth correctly or otherwise keep the phasing identical before/after.
It'll take an afternoon if you enjoy taking your time and admiring your work. You could probably whip it out in 2 hrs if you were hurrying and knew what to look for.
The only tool that really helps is the idle pulley adjuster wrench for setting the belt torque. I've gotten by with using a Crow's foot on the pulley with a torque wrench. You can get by with "feel" if you've done this before on Ducatis.
Oh, ball-end Allen wrenches make the plastic cover removal easier.
Taken from the AUS COG list