Ok, first of all, I am new to the site, but have been reading on here for a while. I have read a lot of knowledgeable, and helpful posts and I'm hoping one of you can help me with something.  I have a 2014 Strat that I absolutely love. I bought it in April of 2015 and have been riding as much as I can.  I have done all the proper maintenance to my machine, wash or wipe her down after every ride, keep her as pretty as I can! The other day I was on my way to work, and all of a sudden she lost power...almost like I was running on one cylinder. The exhaust profile increased in volume, and she would not stay running unless I was giving her about a quarter throttle.  I know its full of fuel. I know she has spark. I used a bore scope just to curb my curiosity, only to find the intake valves are working as they should, but the exhaust valves won't hardly move(maybe a thousandth or so).  MIND YOU.....I ONLY HAVE 8000 MILES ON MY MACHINE. After reading some of the responses on here, I feel like I have come to the right place for advise.  I know the factory warranty ran out like 5 months ago, but I bought a Strat mostly because they go forever, and reading about how much you guys praise them.  I don't know what to do from here.....HELP!!!!

Hi zach141b,  In answer to your questions
1. I took it to the dealership to have the maintenance done.
2. This was the first and only problem I have ever had with it. Never leaked, or popped, or anything.......
3. We removed the plugs and inserted the bore scope, the piston looked fine. we bumped the starter several time in order to actuate the valves.  I had 2 certified motorcycle tech look at it, and they both suggested taking it to the dealer. Just sucks, because I absolutely love riding it.
I guess at this point, I'm looking for some direction in all of this.  Thank you for your input!

2. This was the first and only problem I have ever had with it. Never leaked, or popped, or anything.......

If it only has happened one time, I would be writing it off as a fluke.  Chances are, if it only happened once, the dealer's tech will not be able to reproduce it.  If it repeats, record the speed, RPM, what gear you were in, and anything else you can think of.

If your exhaust valves "really" weren't opening, the bike wouldn't be running.

Previously, you said you knew it was getting spark.  How was this tested?

Disregarding the spark question--I'm going to guess you've got lifter problems.  That's not unheard of on these bikes, and it certainly could impact the valve operation.

Unless you're really well-equipped at home, I'm gonna have to go with Jack above, and say take it to the shop.

Sorry.

Hopefully, you'll report back with a fixed bike and what the solution was. 

Bad lifter. 

Ok, so the dealer called me today with a goodwill offer. The issue they have detected is the exhaust lifter has a hole in the bottom of it and the cam is washed out.  They attribute the problem to the bike sitting at the selling dealer for a year before I purchased it. Told me it was nothing I have done. Their offer was they would cover the parts (about $700.00) and they want me to cover the oil change and labor for the work (about $1200.00). I understand I am 4 months out of the warranty, but holy hell, with only 8500 miles on the bike, and to have a catastrophic failure like this is unacceptable!!!  Am I wrong for being totally pissed off about this??

Thank you zach141b!  I went to dealer, then called corp today. Im going to try back to dealer tomorrow, and the selling dealer as well.  If I do not get anywhere with them, then I will use the info you have provided.  Think that is a good way to go?  I just can't believe that Yamaha would allow something like this to happen....I deal with goodwill all the time at a very large automobile dealership, and this would not happen in this dealership.....!