As I never ever need to read the manuals, I google and assumed that the Megelli engine took engine oil (eg 10-40 w) and the gear box took gear oil (80-90W) So I drained and filled the engine oil via the oil cap on the right hand side and drained and filled the gear oil on the left hand side via the plugs. After that, the bike would not start well and when it did, I could not find neutral and the bike would kick forward on the starter when in gear even with the clutch pulled in. After reading the user manual again it dawned on me that the stated 1.5 litres of oil capacity was probably both the engine and gear oil, as the user manual failed to mention any gear oil specs. Note some sites also mentioned that bikes could have both types of lubrication systems (eg I assume since it had oil plugs both sides it was a dual system) It also explained by the oil glass sight always looked full and why oil sometimes came up via the breather pipe Anyway, after draining all the oil again into a 4 litre bucket (almost full and mixed 50% 10-40W and 50% 80-90W and dirty) and only filling back with 1.5 litres of engine oil (to the sight glass level), surprise surprise it started well and the neutral issue and in gear kick issue was gone.
My moto guzzis take engine oil, gearbox oil in the gearbox and gearbox oil + Molybdenum Disulfide in the bevel drive unit that transfers power from the shaft to the back wheel.. I’m guessing few folks new to old moto guzzis would “guess” correctly how to do a fluid change. I’d highly recommend getting an owners manual at least, or preferably a workshop manual, and learning as much as possible about how your bike likes to be maintained. Worst case scenario incorrect maintaince in motorbikes can kill you.
