Yeah, might be. It's the only thing I didn't change as it was running very smoothly when I serviced it. I'm also waiting until I'm in one place long enough before I order an O2 sensor as that went a few hundred km's ago.
One thing I forgot to mention is that when I accelerate hard the revs sometimes pause at 3,000 or 4,000 RPM for a couple of seconds and then continue. Haven't noticed this before either.

