I had to replace the welch plug on my 2005 DR-Z 400E (checked the valves, etc) and after putting everything back together, I discovered an extra bolt (with a seal). It had some dirt on it, so I'm assuming it's an external bolt, but I did a pretty thorough search of the bike, and couldn't find anything missing. Plus, it's somewhat unique as indicated in the attached image. I went through all the parts breakdowns, and it certainly matches the bolt and gasket on the Camshaft - Valve diagram - BOLT,6X16 09135-06027 (replaces 09135-06022) however there's no information on where it goes. This post http://www.thumpertalk.com/topic/543552-decompressor-part-numbers/ refers to it as a shaft retaining bolt. I certainly don't mind redoing everything I've done, but the fact that it has some dirt on it makes me think it's external, not internal. Thanks in advance for any assistance.