The 668 sportster was marketed in yellow/black or red/black, with metallic
grey on some areas, such as the bottom of the fairing and on the small side
covers. Its main styling difference from the 650 Sport/Formula was its new twin
(round) headlamp fairing, in place of the earlier model's single oblong light
was also a half-faired version of the 668, the Diamante, with a Ghost-type
steel tubular chassis.
Technically, the 668 was supposed to be superior to the 650. In fact, it not
only used the same engine size (668cc), but also, except for improved engine
components to erase problems that had been experienced on some 650s, was much
the same. The early 668s had the 650/Ghost series exhaust with its ugly
collector box, but the Ghost Legend/Strike revised exhaust pipes did provide a
genuine improvement in mid-range power.
Instead of making significant improvements to the 668, Laverda's
engineering and marketing men preferred to keep their powder dry, waiting for
the next stage in the evolution of the dohc parallel twin saga. Their
seven-fifty water-cooled version debuted at shows around the world at the end of
1996 in prototype form, and entered production in late spring 1997. This
important engine and the models it spawned are discussed in Chapter 15.
Over the weekend of 17-20 July 1997, the existing owners of Laverda I.mo.la
(in conjunction with Moto Club Breganze) celebrated the 50th anniversary of the
marque. Over 1,400 enthusiasts were greeted at the gathering by the Mayor of
Breganze, Dott. Francesco Crivellaro.
650/668 Technical Information
All 650 and 668 models detailed here used the same basic 668cc (78.5 x 69mm)
oil/air-cooled 4-valves-per-cylinder with dohc and Weber-Marelli electronic fuel
injection. This was originally designed by Angelo Ferrari back in the late
1980s, and was based on the Alpino unit of a decade earlier.
Few problems were experienced with the early 650 Sport models constructed
from component parts already in stock after the Tognon takeover in 1993.
However, with some later engines, mainly those built in late 1995 and early
1996, such as the 650 Sport and Formula and early 668 models, the following
problems were experienced. They were put right under a programme carried out by
Laverda and its local agents - in the UK, Three Cross Imports Ltd.
1 An improved cylinder head (manufactured by SCF of Reggio Emilia with new
oil ways and new valve seats superseded the original design. It was usually
supplied with valves, springs and buckets, but using existing cams and rockers.
2 Piston modification using different type of rings.
3 Original cylinder heads were thickly finished in paint. This was found to
stifle the cooling process, so subsequent heads were finished in a fine
sprinkling of metallic particles, to increase heat dissipation.
4 Alleged crankcase stud breakage - usually caused by incorrect torque
figures. It is not recommended to exceed those advised in the official workshop
manual for each model.
5 Generator, clutch and balancer shaft nuts. In the spring of 1996, the
original castellated type were replaced by conventional hexagon type, to prevent
them working loose, particularly the one keeping the alternator in place.
6 From Ghost engine number 2114, the oil pump set was changed for an upgraded
type. Most 668s and all Diamantes had the improved type fitted as standard.
7 From late 1996, a new type of exhaust crossover pipe was fitted to replace
the huge collector box on the 650 Sport, Formula and most Ghosts and 668s. This
saw the two header pipes siamesed under the engine with no collector box. This
change provided greatly improved mid/low-range engine-torque characteristics.
8 Electrical problems may be experienced on all the air-cooled 650/668
models. This can usually be traced to the fuse box and relays located under the
rider's seat. To prevent this, these components need to be cleaned, and sealed
with a silicon rubber sealant once everything is 100 per cent dry. Vaseline
should be smeared on the blades of the fuses, and the relays fastened in place
with cable ties. Finally, a small hole can be drilled in the base of the small
plastic cover that fits over the fuses. This will prevent water collecting