Boy was that fun(not). Just got done adjusting valves on a used 2005 c50 I got cheap ,It did not run when I got it.Been setting for over a year.So you know what gas tank,fuel pump and injectors where like.Cleaned tank,replace fuel pump(with aftermarket it was cheap but works great)Pulled injectors and had them cleaned.It ran after all that.But decided to check valves owner did not rember it he ever had them checked..Had 20414 miles so I did it.Like you all say it is a job.But I did find a tool that is great to adjust the bolt with.If you have a old time glass cutter with the three slots in it the first one is just right to fit adjuster bolt.I am 71 so I have those kind of things.LOL I think they still sell them.And yes they did need a little adjusting.Runs good now and yes it sound like a sewing machine but run better now.Hope this helps someone trying to do this.Learn how and stay a way from dealers.Save the $300 plus they charge and buy some cool stuff for the bike.Have a great ride. DaveG Dade City fl.