I'm certainly not a mechanical expert, engineer, Shazaam, or whatever, could be best descibed as an 'armchair expert' having read a lot on the net.
What i can talk about is the four, 4 valve engined bikes that i've covered quite a few miles on and related rocker experiences.
ST4 only did 6500 miles, so too early for any problems. Rockers not checked at 6000 service though.
ST4s just under 20,000 miles from new, no rocker problems (and yes they were checked). Maybe i was lucky or the rocker problem improved by 2001.
Year 2000 SPS bought secondhand with 7000 miles on the clock. Soon after getting this bike it needed 2 rockers and Nelly at Cornerspeed also reckoned that 2 others had already been replaced already. This bike was sold to my good mate earlier this year and i still ride it at times now. It has now done over 17,000 miles, just had full service by Nelly and clean bill of health on the rockers. I have heard that the cams on the SPS give the rockers a harder time as well.
Year 2001 996R with the first 'stretta engine, again bought early this year secondhand with 7000 miles from the brother of a lad at work so i knew its history. This is now just passed 14,500 miles and (touch wood, fingers crossed etc) no rocker problems, though i have read that the 'stretta engines do not suffer from rocker problems.
My armchair expert research (the Sigma Performance site has a particularly good article
www.sigmaperformance.com )
concludes that 3 factors other than luck affect rocker wear.
Firstly the older long stroke 4 valve engines can take upto 90 seconds to start getting oil to the rockers on start up, therefore carefull start up/warm up before riding away is important along with not thrashing a cold engine before it is warm (although this last point would apply to any engine, being in the courier trade i have experienced a few high mileage bikes and vans) thereby allowing 90 seconds to get oil to the rockers. Annoys the neighbours but cheaper than new rockers.
2.
Although Ducati rec 10/40 oil, various peolple suggest 15/50 is better as being thicker the oil film clings to the rockers for longer, therfore protecting them for the next start up. I'm also from the school of thought that engines used frequently are better than those started once in a blue moon.
3.
Ducati themselves say that it is absolutely crucial that valve clearances are set correctly and this affects rocker wear. If you use a mechanic who may not do the job to perfection, and it is not an easy job you may suffer the consequences.
My experience would suggest that the 'stretta engines have cured the problem, and that in the case of the SPS with its evil cams (4 rockers in its early life) then 10,000 miles of carefull warm up, using 15/50 oil, regular use and first class servicing by Nelly at Cornerspeed has resulted in no rocker problems.
I must add in Nelly's defence i'm sure he doesn't guarrantee no rocker problems, and i'm sure other experts do the job properly (but some may not), i can only speak as i find. Finally i have also heard that Ducati have produced numerous updated rockers to try and cure the problem, and it may be that the newer rockers have done so, but there are still a lot of the original rockers, as well as the original cams in the SPS.
To sum up, warm up carefully for 90 seconds, use a quality 15/50 oil (changed every 3000 miles rather than 6000 miles), and correct valve clearances, minimises the risk of rocker problems in my opinion.
07-Sep-2005, 12:35 
Linear Mode
