The 668 motors are in a high state of tune for a parallel twin, and to cope with this Laverda fitted an oil cooling system to dissipate heat from the cylinder heads. However, the engine still runs hot and can overheat at low speeds, making the bike not well suited to stop/start driving in heavy traffic, particularly on hot days.
To address these cooling issues, Laverda increased the oil pump speed by changing the driving gears, hence increasing oil flow and pressure. According to Mick Walker's recent "Laverda Twins and Triples" book, this took place from Ghost engine number 2114. Coupled with this there were redesigns to the oil galleries in the head and an additional coating was applied to the outside of the head to increase radiative cooling. All of these changes should, I believe, be incorporated into the upgraded cylinder heads.
I have seen one report at least of a problem with the oil temperature gauge. This can lead to a false sense of security, with the temperature shown on the gauge not reflecting the true state of things. In the case of this particular bike the temperature gauge stopped at 90, although the engine was considerably hotter, leading to the engine seizing and destroying the cam shafts. If you are regularly riding in adverse conditions it might be worth while borrowing an electronic temperature gauge to calibrate or corroborate the temperature gauge fitted.
The high temperatures in the head would also suggest that it would be wise to follow the factory recommendation of a fully synthetic oil, such as AGIP 4t or Mobil 1 4T Super Racing. Fully synthetic oils have a higher resistance to extended high temperatures. See the lubrication section for more details.
© Steve Carr, 2001-2007
Site created February, 2000. Last modified Friday, May 15, 2009
30 May 2005