wv said, Sled was new in January 2005 - 0 miles, so maintenance is not the issue - I pulled the PV's as I just had a friend bull the PV's off his F5 (4500 miles all amsoil interceptor) and they were spotless, and I mean spotless. I will pull them in about 500 miles and see what they look like.
new sled, rode most of last year, put away without cleaning valves, may have contributed to the excess difficulties of cleaning and gumming of valves. your also comparing apples to oranges with an f5, higher mileage, higher revving sled, different oil, different jetting, and oil consumption. just an observation.
and without saying yamaha has a bad pv design, i just want to point out again, the electronic operated pv's have more oiling, cleaning, problems than a gas operated non electronic system in my observations. the electric valves need more attention.
i am not sure why some srx's and vipers are cleaner than others or why some cable ends pull through while others that were "more abused" (ie: less maintainence) remained active and in good working order. all i can think of is the different riding conditions, storage, and oil pump settings makes all the difference in the world.
after i understood the problems i was seeing with the build up on the valves, i adjusted my maintainence schedule for them, as my oil consumption was where i wanted it to be. now like i said i wont go over 1000 miles without cleaning them. when you up the maintainence schedule, the cleaning takes about 45 minutes from start to finish, and you have piece of mind they function and are clean. ski