Sticky upshifting

I have an issue with occasionally stubborn upshifts usually 3rd to 4th but it has happened with others gears. I am coming up to 5000km on the bike which is a 2011 WRR. I did the last oil change at 4500km which made no difference. I switched to 10w40 from 20w50 Yamalube. It is worse when the bike is cold but has still occurred at the end of a long ride. Typical scenario is the first upshifts are fine, but the following ones are sticky. When I first got the bike and now as well I find it also goes into neutral instead of first coming down from second. These all happen in summer temps as well as cooler weather riding. I did call my purchasing dealer and they said they would register the issue with Yamaha but didn't hear back yet. Its not a big boot issue, if you know what I mean. I was wondering if something like this could end in a damaged tranny. Of course I will be contacting the service department again but wanted to see if anyone else came across the same problem.

Yawny

Is your clutch cable adjusted properly? My WR shifts like butter compared to my '03 CBR 954, but I can have hard upshifts when the cable needs adjustment. I don't remember the last time we had a warrantable transmission problem in service. Usually, it's linkage adjustment (no linkage here), bent shift forks (been shifting without the clutch or missed a shift?) old oil or rider error. Since it is intermittent and there does not seem to be a common circumstance when it happens, I'd say rider error. Are you sure you're not pre loading the shifter? Try adjusting the pedal either up or down one spline on the shaft.

My Wr250R shifts perfect except for those occasional misfit ones. A couple other riders commented on the great shifting after riding it as well. I can't say that I've never blown a shift, but I would think damage in the tranny would be evident more often. I wish it was rider error, and had a hard time convincing myself it wasn't. I was thinking of mounting my Gopro down there to perhaps reveal something. It happened again at the beginning of my last ride and once more near the end after a 10 mile haul down a gravel road. I was shifting after a sharp corner heading to the hiway. Your preload comment is interesting, I will have to observe that possibility as well. This past ride I did pay attention to the shifter position. The engagement is actually at the bottom of the upshift and when I put light pressure on the shifter (without shifting ) I can feel that its engaged. When the incident happened it seems the the shifter moves up without the click. Does this shed any light on the subject? Its hard to pay attention when you're in traffic and I don't like gawking down too long with my eyes off the road.

If you can access a parts fiche look at the diagrams, in order, for shift shaft, shift cam fork and then transmission. Basically, your foot moves the shift lever or pedal. The lever turns the shift shaft. The end of the shift shaft turns the shift cam or shift drum. The ramps in the shift drum push the shift forks side to side. The forks push gearsets either together or apart on the transmission shafts. Gearsets pushed together link via the "dogs" on one gear dropping into slots on the other gear. All the springs, washers, etc. on the shift shaft picture space everything correctly in the cases for smooth operation and return the shift shaft to a "neutral" position (neutral in this case referring to niether upshifting or downshifting not first/neutral/second). Lots of moving parts that do not move very far and need to move a lot of mass, relatively speaking in a short time frame. Also check out You tube videos "sequential gear selector" and how a motorcycle gearbox works" both informative. Any bent or broken component would most likely cause missed shifts more often. 99.9% of my missed shifts have been caused by an inaccurate left ankle.