Is this too much oil?
Itís right where the top of the window ends, so a little over the max line. I bought the bike a week ago and this is how it came- the seller assured me this is where it should be. The manually obvious says differently which I just decided to heed tonight. The bike has seen a decline in performance since I bought it last Friday- engine seems like itís working too hard while climbing gears at 7 to 8,000 rpms and sometimes will be rev very briefly while hard accelerating as if the clutch were disengaged when it isnít. Could this be related to there being too much oil? Have I destroyed the engine in a week? I ride it pretty hard and have definitely made some clutching mistakes as Iím a beginner that have undoubtedly been hard on the engine, but nothing insanely bad. I love this bike to no end. This is slightly killing me.
Sounds more like a clutch problem. What is the play in your clutch lever? Is it to spec with the manual?
Your engine is fine if it runs.
My advice: Stop riding the moto. It is sick. Drain the oil. It looks very light in color. Give it the smell test: does it stink like gasoline? You may have fuel mixed in due to a faulty injector, worn rings, overly rich fuel mixture or another reason. A crankcase that full of oil is going to cause the bike to run poorly.
Light in colour? New oil.
A crankcase filled to the top of the glass will not greatly affect performance. A crankcase filled to the filler hole will.
But I reckon the bike is running on some weird oil, and possibly overfilled too.
The bike has 13K miles and ran fine the first few days, so I doubt the clutch wore out in that short time-frame.
the damage might be already done though, who knows...
So for a few days it ran fine?
Then it is not the weird oil unless it fouled the plugs.
It is not the overfill unless it fouled the air filter.
Sounds more like a clutch cable adjustment.
The symptoms you're describing sound a lot like a slipping clutch.
Also as you say you are new, are you holding on to the clutch lever, applying pressure and not realising it?
It can happen just like resting your foot on the rear brake lever and not realising it.