Hello, I am a new member and a new atv rider...I have 10 years experience on street bikes but have moved to Portland OR and the seasons up here are so short maybe 4 months so I bought a 2009 YFZ450R Special Edition.

My questions are because I do not know how sensitive atv engines are but I just brought my bike into my mechanic for a GYTR air filter, NEW Yosh RS2 Titanium Full Exhaust, Power Commander 5, red anodized braided steel break lines, Black rear sproket Red anodized chain and dropped the front sprocket down a tooth to 13 teeth and a bunch more custom work..I will send pics when it is done.

But this last summer I rode it at the dunes almost every weekend fully stock...with these few upgrades should I notice a significant increase in power and tork especially with the front sprocket being dropped down a tooth?

Thanks for everyones time and responses

 

Welcome! I am willing to bet you quite a bit of a power difference with that setup! Good luck let us know how it works.

 

The gearing change alone should make that bike scream coming off the bottom and will absorb some of that power loss from the sand as well.
What you have packaged up there sounds to me like a good combo for the riding you are doing.

 

Oh, man will you tell a difference.

 

Sweet Thanks guys....I am hoping for a huge change in low end...I mostly ride and got addicted to "Tree Shots" as they are called out here and well some are extremely verticale with little to no launch pad so I need a LOT of snap to get up and out plus jumping spines between trees and shots and I ned the snap to get back on it right away....So I should be good right? I am biting at my nails day and night to get that thing back

 

wellcome to the club, i bought my red/white se. march 09'. in stock form the YFZR fast enough for me, but being power hungry and a desire to get even more power i went with the typical mods, pipe, intake, p.c.5. i'm well satisfied with the results. but i to was concerned about this tight tollerance engine. i have about 16 or so hours on it, and our local yamaha tech. is one of the best. he checked and adjusted the valves for break-in. and through basic research,talking with my mechanic, my own mechanical knowledge, and the fact that yamaha builds a great reliable machine. the YFZR when maintaned will hold up to it's name and quality. now as a race machine they do require more tlc, it just depends on how hard we are on them. when riding in sand with aggresive tires, and the throttle pinned constantly, the motor gets stressed out more than a sunday trail ride. sounds like you got a wining machine, i think the YFZR was ahead of it's time... i really enjoy mine, i'm positive you will enjoy yours. hope i was some help...