97 yamaha blaster power loss please help!!!

[Vinbianco]

I have a 97 yamaha blaster it's been bored out has an fmf pipe, the problem is it runs fine sounds fine when you ride once you hit 3rd gear there is a huge power loss. Also throughout the other gears too if I climb a hill it will even die when it's too much of a hill for it, I know something's wrong with it I was flying up and down hills a week ago and now it's got no balls any help would be great guys

 

[Blasterr]

Leak test? Compression test?

 

[Awk08]

/\ that

also.......... change plug, clean carb, check/adjust floats and pilot/airscrew adjustment, check reeds for cracks/chips/breakage, and plug chop main jet. < has it been rejetted for these much colder temps ?

most of that info can be found in here....
Engine - Carburetor at BlasterForum.com

 

[bummer981]

Also how is your air filter?