Losing 1.1L of oil in 600 miles is a LOT! That’s 2-stroke levels of oil consumption. If it was burning it at that rate you would easily be noticing a plume of blue smoke in your mirrors, and if it was a leak, you would definitely notice a serious pooling of oil under a parked up bike.

Now, the following is just an assumption, but it could explain your missing 1.1L of oil…

You say you changed the oil and added 2.6 litres. When you drained it, did you also drain the sump? If you didn’t then 2.6L would have been too much oil by about 0.6 litres (which is approximately the sump capacity). This excess oil would then have been blown out through the crankcase breather into the airbox, some will be inhaled by the engine and the rest (in fact most of it) will collect in the bottom of the airbox and its drain tube.

When you drained the oil (after 600 miles) 0.6L would have disappeared in the airbox (as above) making your original 2.6L now approximately 2.0L. Then, if you didn’t drain the sump the second time either, there would be an additional 0.6L in there too, bringing your original 2.6L down to roughly the 1.5L you ended up with.

Is your airbox full of oil? Did you drain the sump? Did you follow the add 1.9L, start and rev the engine a few of times, then top up with the remaining 0.7L rule?

Also, are you measuring your oil level on the dipstick after the engine has been running or a few minutes or after a ride, or are you doing it on a cold engine? If it’s the latter, you won’t see anything on the dipstick at all as a quarter of the total oil volume will be sitting in the sump waiting to be scavenged back up to the tank.

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