Loss of power then fine? ?

[darrsi]

I did wonder about the air filter. I haven't checked it, but was thinking while I did I could replace it with a k&n??

Loss of power under pressure could well be a grubby or blocked air filter, i've just had a similar thing happen to my bike.
I have the K&N on mine, as do quite a few people and it does make a big difference in my opinion.
Whichever way you go, just don't buy the cheapest air filter out there, either try a K&N which are washable or an OEM Yamaha one.