Hi folks

My Z has after the last big service with valve adjustment experienced increased fuel consumption. Its not a whole lot, I have figured it out to be around 10 %, but still - there is definitively a change in fuel consumption. I noticed this after the service but the bike wasnt used much the last two months before service so something might have happend at that time?

My bike is 2011 Z, it has LeoVince pipes, DNA airfilter, Kev both mods (fuel and O2) I run 15/48 sprockets.

Before service the fuel consumption was always very near 25 km on one litre which is approx 71 mpg. Of course if ridden very fast on highways or slow on bad roads/dirt roads the consuption would increase a little. But with my riding style and not too drastic roads it was really an easy task to figure out this. It was almost always very near this figure.

After that service the consumption is around 22-23 km pr one litre or 63-64 mpg. And I havent changed riding style and there isnt anything else that comes to my mind that can cause this. The bike has done + 70 k km now. The engine and the bike itself feels exactly as strong as before and rides exactly like before as far as I notice.

At the last service the garage said the valves were well within specs so they just adjusted them a tiny bit. I also had new tyres fitted and I have also some extra headlights mounted, but they are quite small in size and cannot explain a 10 % increased fuel use. New rear wheel bearings was mounted also.

Both wheels seems to turn round ok, air pressue in tyres checked every second day of riding and are always near the specs 40 PSI rear and 35 front. I ride with a heavy loaded overland rigged bike. Air filter was cleaned and lubed when serviced and I have checked it later and it seems fine. Chain is lubed every second day of riding and adjusted once (it was too tight out from service)

What could cause the - maybe not remarkably dramatic increase in fuel consumption, but still quite noticable change? Any ideas anyone?

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