Oil feed pipes to cams -- rubber cap

[Ian (GPX)]

https://www.gpz400r.pwp.blueyonder.co.uk/images/oilpipes.jpg

OK, need some help on this one.

In the above picture you will see two oil feed pipes that feed oil to the cams on a GPZ400 / 600 R.

Part no 11012 is the bit I have a problem with at the moment, it's a rubber cap that fits over the top of the oil feed pipe, the head cover has mouldings for these caps to sit in, it looks like the cover holds these pipes in place with the caps. There should be four of these, but I only have three (could not find the forth one when I took the cover off the head). If I put the head cover (rocker box cover) back on with just three of these caps, would it cause a problem ?

I plan to visit my local Kaw dealer in the morning to see if they have any in stock. Does anyone know of other places that may stock this cap ?

TIA.

Ian.