[Gearbox Paul]

I just completed the valve clearance adjustment on my 08 250r. The bike has 21000 km (about 13000 miles). I'm not the original owner and I don't have any maintenance history on the bike. So I don't know if the valve adjustment was ever done on this bike.

When I first checked the clearance, all intake valve were within spec. But all exhaust valves were too tight, with some well below the acceptable range of 0.22-0.29 mm. On one of the exhaust valves on No. 2 cylinder, the clearance was below 0.127 mm (0.005") which is the smallest feeler gauge I have. Yet the bike ran fine.

I didn't have a shim kit when I did the work, so I went to the two local motorcycle shops in town to buy the shims I needed. Unfortunately, their shim supply was not complete, and I didn't get all of the shim sizes I was hoping to get. And there is no Kawasaki dealer nearby. Anyhow, I completed the work with the shims I could get and ended up with all but one exhaust valve in spec. The valve that is out of spec is on cylinder no. 1 and its clearance is between 0.178 and 0.203 mm. That's better than it was before adjustment, but still out of spec. Running out of time, and not having any other shims available, I elected to put the bike back together.

Which leads to my question: how soon should I correct the remaining valve that is out of spec ? Given that the clearances are much better than when I first measured them, my gut tells me that I don't have to rush to correct this right away. But what if I wait until next winter (I typically ride about 2000 miles per year) ? Is that too late and am I running a serious risk of damaging something? What if I wait until the next scheduled valve service in 7500 miles?

I appreciate your input. Sorry for the long thread.