The Bricks have a combined water/oil pump and if a seal goes cross contamination can occur. There is a weep hole underneath the pump check it for leaks. Bricks need to be ridden and when left sitting the pump seal can harden and the rings can stick causing low compression and or oil consumption. Injectors are on the other side of the valves they do not inject straight into the combustion chamber.
Regards Martin.

Ff223 wrote:[size=16] . Can the injector seals deteriorate and cause loss of compression?

No, that's highly unprobable.

And can water get into the oil at the pump.

No, the design of the pump prevents it.

The general vibe I'm getting is these head gaskets never fail so it's wise to look elsewhere before taking head off?

They do fail...

Only 20750 genuine miles on her. In the last 7 years only 4 miles were put on her in 2022 which is a bit suspicious to me.

Never trust a K100 odometer...

Thanks everyone, I'll start digging

Howdy. Thread moved from Troubleshooting - General to Troubleshooting - Engine & Transmission. This is done for easier searching in the future for anyone who might need to look it up for vital information.

Ff223 wrote:Thanks everyone, I'll start digging

Before you dig too deeply, let's pretend that the Brick has only been ridden four miles in the last seven years. It wouldn't be the first Brick to have been neglected that much.

A Brick that hasn't been used much in seven years is likely to have crankcase oil diluted by condensation; condensation can be the source of the water in the oil. A leaking water/oil pump seal can also contribute to water in the crankcase, as Martin has indicated.

A Brick that has been ridden only four miles in seven years is likely to have stuck rings causing loss of compression during a compression test. Remove all the spark plugs, spray fogging oil into each cylinder and then do the compression test with the throttle twisted wide open.