It depends on tires also. HMF doesn't use slicks or Hoosiers on their dyno numbers... Those alone will add 4-8hp to a dyno. Just go to GT's website. He even says so... If you ride w/ Hoosiers on a flattrack then you have close to 50 for theYFZ and if you don't flattrack your hp numbers are HMF style... Food for thought.

 

The YFZ tested was wearing Hoosiers.