Papi, the technical guru on the French Twinning site, has published a method of modifying the auto tensionner to extend its stroke which includes drilling an additional weep hole for lubricating the unit and redrilling the location of the spring pin stopper. That may be what you were recalling/dreaming. I published an english tranlsation of the method on the old site a while back and I probably still have it somewhere on one of my drives. This modification is relatively simple and should be done on all automatic tensioners which were only found on the 650's and turbos in North America but on some of the smaller bores in Europe. I have done it on my main drive and it is still running noiseless after 161,000 km (100k miles)