A part which is a bit unnecessary and adds weight is the secondary air pump.
This blows air in the exhaust manifold to make the emissions look better.
It's common practice in motorbikes to remove this air pump.
BMW is offering a block of plate for the cylinderhead of the S54 to close the hole once you remove it.
Here it is.
Only 16g of weight
Here the pump removed.
1448g
And the pipe with the valve.
252g
So here we have
1.7kg of weight removed with a cost of 25 EUR.
Unlike my Yamaha R1, the CSL is supposed to have a check engine light because I removed this pump.
The engine light didn't come on yet.
I will explain how we deal with this by reprogramming the ECU
