Following the manual, over the years I've added 3.4 Liters after draining the oil and changing the filter. Now I've realized that was probably too much. This time I watched the site glass while adding the oil. After only two quarts the site glass indicated half way between the low and high marks on the clutch cover. I don't know if the new filter is full since I didn't start the bike. The bike also has 16" wheels front and back with the rear wheel on a stand so I'm not sure all the old oil drained out. I don't think that the site glass is accurate since the clutch cover is probably used on different models. But adding only two quarts is only a bit more than half the recommended capacity. Any ideas?

An immediate thought: The oil in the lines and oil cooler take up volume. The best way to fully drain the oil is to ensure the motor is fully warmed and as much oil from the entire system is drained.

Do not gauge the amount of oil by the sight glass until the new oil has gone through the entire system. We add oil to the crankcase, but oil is held in other parts of the oil circulation system, too.

Yeah, fire it up, run it a bit, shut it off, and then take a look at the glass after it has sat a while. I bet you will add more. MikeV

After firing up the engine and then letting the oil drain into the crankcase it took a total of three quarts and is at the maximum mark on the clutch cover..One mistake made was not warming the engine before draining the old oil so maybe some of that remained in the cooler, lines and nooks in the motor. I was waiting for a new battery. Unless the cooler and oil lines are drained, I don't think the bike would ever take 3.4 liters. I also think the accuracy of the site glass is suspect.