While I had the chance with the tank off, I had my first peep into spark-plug access on my 2018 939 Hyper. I pulled off the coil/cap and peered down the deep vertical-cylinder hole and saw this spring resting on the spark-plug top. Ok - the last Duc spark plug I looked at was on my '98 900SS so, yes, I'm rather out of date! However my shock at still not even being close to being able to extract the spark plug was a pisser! At the bottom of the deep cam-cover hole was a white plastic collar and just the very tip of the spark-plug showing. I was surprised that this spring isn't captive in the coil/cap... I have to assume that this is normal, as it's the first time the cap's been off.
No, it's not normal. It looks like the bottom has come off the stick coil and the spring which should locate on the terminal on the top of the plug has come out of it. The collar you can see must be from the bottom of the coil, I can't think how you are going to get the it out.
Thanks for the confirmation Derek - that was my opinion - the white cap is only push-on and has detached, sitting on the plug. At least it works as it is because the spring's still doing it's conduction job. If it were the horizontal one (haven't checked) it might not be so straightforward to get the spring in place correctly...
Can anyone tell me what the (white-ish) end cap is made from so I can plan how to get it out when the time comes... As above - mine has detached from the coil housing (it's only push on), remaining on the plug...
I haven't got stick coils on any of my current bikes so I've no idea. When you get it out I'd glue it back on with a suitable glue. You might be able to retrieve it with a length of stiff wire, like a spoke or piano wire, with short hook bent on the end of it that you can hopefully manipulate down the side of the collar and use the hook to pull it upwards.
Thanks again Derek. It's going to be rubber - probably Silicone - so hopefully I'll be able to hook into it and manipulate it out as you say. +1 for superglue if I don't destroy it... I just looked at the price of a new one Argh.
