Modern Vespa

I changed the final drive gear oil this afternoon and confirmed that Robot is indeed correct….150ml is the correct amount of gear oil to put in after draining. It brought the oil level right to the first hash mark. I actually changed the gear oil on my 2005 GT 200 first just to make sure I had the procedure down before undertaking my new GTS 300 HPE. By the time I did my 300 Super, I perfected my cardboard funnel and didn't spill a drop of oil on my floor.

I suspect the simplest answer is when it reaches the correct level on the dipstick (which is described in the manual). so start with 150, check dipstick and stick some more in.

Thanks! I'll go that route to be safe.

An extra thought, the above approach is smarter than assuming a certain amount because you may have left some in there when draining the old.

if I am not sure I drain into a container and transfer into a clear jar. Mark the jar and put in the same amount. Thanks