For years I have been extolling the virtues of the Bosch Platinum SparkPlug. YMMV. Ten years ago the number WR7DP was the proper fit for Guzzi. Five years ago, Bosch changed its numbering program and this same plug became #4216. It took us awhile to track down that change. In fact, the 4216 box contained a WR7DP spark plug.
This weekend I used the last of my stash on the SPII so I went to AutoZone to replenish. Oops! The entire inventory has been fully recalled by Bosch. New numbers are issued yet again, but there is nothing in the current pipeline to identify the changes or to determine what other plug to use. They have charts of vehicle year-make-model but you know the dull stare you get when you start talking about Italian motorcycles.
Today I contacted Bosch Support and spoke directly with a nice technical chap, and we got the data we need. The exact same plug is stillin production and is now issued under the designation of:
BOSCH PLATINUM PLUS #4016
I visited the same AutoZone store again and looked at this revised number plug. Sure enough, the 4016 box contains a WR7DP spark plug. The graphics on the porcelain are a little different, but the stamp in the hex casting still has the good old original number. Go get 'em.
Patrick Hayes
Fremont CA
Using these plugs in EV, SPII, Eldorado, and Monza.