Well, it's due for the 1,000 mile oil change. Couple of days ago, dumped 5qts of old oil, refilled with 3qts of fresh oil. Replaced my BOF (side filter paper sleeve).
Whut the........
Instantly, and after about 100 miles of riding today, I have my easy shifting, neutral finding back!
Son-of-a-gun.
It was the oil!
Mrriggs had mentioned awhile back that dragging clutch for him meant time for an oil change.
I'll keep monitoring this new Valvoline VR.
Considering trying a full synthetic after that...
To be honest, I've not done enough miles on the XS to be aware of its oil peculiarities and preferences, and apart from that, there's a kind of total-loss / partial replace system running in it at the moment, so it's continually getting topped up with fresh oil, mostly a racing 20W50 I can get locally, with a high zinc content.
Otoh, one bike I know intimately over many long years and literally hundreds of thousands of miles is the Suzuki GS850.
Fwiw, here's my experiences with various oils over the years (by far and away, 90% car oil, as bike oil is overpriced here).
There's not an oil that lasts beyond 2000 miles in the Suzuki engine. Sure, you can run it to 3K if you want, or even 4K, but what happens at 2K is quite noticeable - the gearshift starts getting a bit clunky. In the early days, it was received wisdom to change out the oil at 2K, so that's what I was doing. From time to time, I'd try to extend the change interval, but without fail, at 2K, once again, the gearshift told me NO.
My view is that if I can feel a mechanical effect from worn-out oil allowing the change shaft / drum / gear shifters to touch each other more closely through an oil film that's definitely sub-par, then I don't know how the most essential element of the engine is doing - the crankshaft.
So, every 2K, without fail.
A few years ago I tried a synthetic 5W40 for winter (to eliminate cold clutch drag), and that was good, it even liberated an extra couple of horses, but it pegged out exhausted at 1700miles, so much for that.
The good news is that the Suzuki engine isn't fussy about the oil its fed with, so I'd keep an eye open for end-of-line (good brand names) oil bargains, and the cost of 2K oil changes was minimised. I'd be mostly running 15W40, some 20W50, sometimes 10W40.