very easy to install , if you have ever replaced a piston on anything. Or if you have some common sense and some mechanical skills. ( motor out of bike, cam chain tension-er out , cam caps off , cams out , head bolts out , head off , cylinder off , replace pistons , ect...) should see like 70+HP total, so if your bike makes 50-55 plan around 70 if it makes 60-65 now plan around 70-80.