Official Noob Greeter
Join Date: Jul 2007
Location: Humboldt Native, Sacramento Captive
Bike: stupid ones and a Prius
Re: Oil cap blew off today.
If you still have the cap, you should inspect both it and the threads on the cover and confirm that they are not damaged. I have had a lot of bikes and have NEVER had this happen, and I very very seriously doubt that you had enough crankcase pressure to literally blow it out of there. And if it did, it likely left part of the plastic cap inside the engine.
My suspicion is that you didnt tighten it properly and the rpm made it vibrate out. You absolutely should not ride it that way, as it likely will blow out hot oil onto your bike, you, and possibly your tires, which can be extremely dangerous. If its running, the crankcase pressure will probably keep most stuff out of there, especially as rpms build, but its really not something you want to roll the dice on for a variety of reasons.
You can safety wire the cap, but DO NOT LOCTITE IT. Also, make sure that the Oring on the cap is intact and not worn, as it provides some of the necessary friction to keep the cap on and from turning.