pipe port polish bigger carb. These are the basic things to do to get more power out of any motor. Dont forget to get rid of that air box lid. Oh, sorry I forgot it was a 4 stroke, get that cam too. You may want to invest in a bigger set of valves and rockers while your in there.

 

YFZ carb. w no airbox, big valves, full port and polish, atleast stage 2 hot cams minimum, 13.5:1 piston. Or sell your save alot of time and probably some money and sell your bike and get one of the better 450s or 700 raptor that are already out. With minor mods they will still be faster than yours even if you do decide to go with a big bore kit. Just my opinion I have no doubt other will vary.

 

I just dyno'd two Yoshi stroker 450z's. This is a 5mm stroke and 2mm bore that Yoshimura does.. They're porting blows big time and they were redone.. I have the dyno graphs on that Z site that's central.. Can't post the link it will get deleted.. Go into the tuning and maintanance section on that site. The two Yoshi were just slightly different builds..

I have an Athena kit. Runs great, but it's ported, carb cams ect..

 

Now stroking and boring are 2 different things all together. Just boreing out your cylinder with no other work done does not give any real noticable power gains, stroking can affect your torque #s drastically, add all of the above and it will kick a**

 

LMFAO!!!!!!! Power is not made with displacement!!! Yea ok. I just put a athena 435 big bore on my bike, I have everything else done beforehand so i know how the bike feels. I put the big bore kit on with no other changes. WOW!!! It flat out hauls now. Suprising that 35cc makes that much difference.