Here's from the factory repair manual. The relief spring isn't the issue as the pump doesn't achieve relief. All the arguments as to why replacing the spring will make a difference or why the spring is allegedly low is based on false assumptions.
The main argument is the low relief pressure is to meet emissions regulations. That's hog wash since the least efficient way to run a pump is to oversize it and bleed off excess flow.
A positive displacement pump will not increase pressure with a higher relief pressure.
There's plenty of other reasons it doesn't work. Don't pay attention to the solutions the Facebook group puts forward.
If the fix was the $1 spring, KTM would include it in the repair. Instead they replace the cam, followers and the head in model years that did not have the additional metal filter installed in the head.
Do you know how small the oil jets are? .5mm in the head and .3mm in the clutch (.020" and .012"). If you have particles that big making it through your filter, you have bigger issues. They're huge compared to what makes it through the filter.
If your shop is telling you to run 15w-50 vs 10w-50 because your location is warmer than Europe, they don't understand how oil works.
Basically what I'm getting at it they are trying to fleece you for money based on the current KTM drama.
One of the great things about including documented evidence is that it can be checked. That is why people who are lying to you are deliberately vague and resist putting anything in writing and avoid responsibility -- liars exhibit a smell that is universal.
Here is the oil listed in the Invoice:
The guy who performed this work also has a KTM 890 Adventure and he, as one would expect, performed the same spring fix on his bike. He speculated that Euro 5 might be enforcing less oil in the emissions, limiting pressure so that emissions are constrained. He said the more oil that flows the more volume finds its way into burnt exhaust, which means higher emissions. My speculation is that this specific engine might burn more oil than allowed under Euro 5 and they solve it with a lower pressure than what the engine is designed for. To me that is a logical speculation. To someone else it might not be logical or reasonable.
I had the front sprocket replaced with one tooth down because the gearing of the 890 Duke R feels too tall for regular street and highway. To me the stock gearing is not a good match for the character of this engine except perhaps when you run it on the track in the high RPM range. My speculation was that it may be tall to achieve Euro 5 efficiencies. We know Euro 5 is making manufacturers of ICE vehicles jump through hoops and do regulatory gymnastics. It is just getting worse.
We know the fuelling on Euro 5 performance bikes is all kinds of F***ed up to the degree that AFR is stretched to buggery and cause engines to run far too lean and hotter than they are designed to. This can also cause all kinds of user control issues. Just take a look at the 1290 SDR and the lack of refinement the Euro 5 "tuning" causes. That bike goes from a rough, unrefined beast to a very controllable refined machine with a good dyno tune and some care in the setup. But this effectively wipes out any Euro 5 contortions.
We know that the EU want to phase out ICE technology due to a disingenuous, unscientific political ideology. They also want to remove heavy manufacturing from Europe (move to China) and are achieving it through a range of policy and legislative frameworks. The same is occurring here in Australia, US, Canada and UK. Coincidence? I think not.
FWIW I will discuss this thread and the challenges to the fix with the guy who worked on my bike. He said he always takes pictures as part of his documentation so will post these up, too. He said the CAMs were perfect on my bike (I asked him to check the CAMs before performing his recommended fix):
Labour to check valve clearances and camshaft lobes. All clearances in spec and all cam lobes are perfect
Bike currently has 9.5K kilometres.