While i was rebuilding my 400ex engine with the mods listed in my signiture, I was told the stage 2 cam and 11:1 piston would make starting much harder. To tell you the truth, the quad actually starts better now than it did stock and its much colder otside now than it was before i rebuilt the engine, as for the bottom end power loss. Its barely noticable anymore and I am really satisfied with the way the quad turned out, but seeing as how i can still modify it further....I MUST! so the next mod will be a supertrapp silencer and new front shocks followed by getting the carb bored out, possibly headers too. Oh yeah, while im at it, I am going to gusset the frame and have it powdercoated silver vein. I plan on spending 5 grand total for everything, including what i paid for the quad, then i'll have something customized to my particular tastes instead of the typical 400cc red or yellow 400ex.