Ok I have a 2003 Yamaha Warrior and i want to get some more power out of it. Mostly all we do is trail riding and i beat this thing in the woods so i want to keep it as reliable as it is now. So far i have a fmf header pipe, fmf slip on, k&n filter, works front shocks, renthal bars, DG front bumper, hand guards, swing arm skid plate, and razr tires. This thing has never let me down except i keep breaking the terminals off the battery but other than that i just keep the oil changed and keep riding. I really think this thing was built on a wednesday because a couple of my other friends have warriors and i tear them apart down low and on top. I bought a dynojet jet kit, and a hotcam but after reading some of the posts i might sell it for a webcam. Is there anything else i can do to get noticable power but keep my reliability? Thanks for any help... P.S. this is my first post so take it easy on me lol

 

The reason your battery posts keep breaking is because you battery is not strapped down. A high compression piston will give you a noticeable increase and still keep it reliable. JE makes a good 10.5:1 piston and Wiseco makes I think a 10.25:1 piston. I'm a fan of JE but after a post on here found out they only make the 366 kit which will max your cylinder out. So if you don't want that I guess Wiseco would be good for you, and yeah if you want max power go with the Webcam. BUT the Webcam .430" may be a little big for the stock piston.

 

My battery still has the strap on it but it still seems to break the terminals, this is the third one to be exact and its getting kind of aggervating. Would i need to bore it any? or change my rods/crank? Im totally new to building a 4wheeler, not if it was a small block ford or chevrolet i wouldnt have to ask so many questions...And also where is a good place to find all this at? I usually order my stuff from RockyMountain but they dont carry Webcams.

 

Toss the stock CV carb and get a REAL carb. First thing you should do!

 

i seggest you to do not try to boost your warrior , first becaust it is air cooled, secondly because you do not know much more about it, and third this will cost you much mure, but all all the best way to boost warrior is , to , change the spocket ratio, change the camshaft for a hotcam, jet thecarburetor using a power jet kit from dynojet, and install a high flow air filter ! Good luck carburetor jetting ca be very hard for beginner ! this take me 1 year to learn !

 

Hotcams are junk.
Jetting the carb doesnt do anything unless there is a problem with your jetting to begin with (ie you added a KN filter or put an aftermarket exhaust on).
Carb jetting is very difficult. Its more of an art than a science sometimes.

 

Make sure the battery strap has the battery tight. If the battery is allowed to move ANY, it will eventially break the cable ends.

You don't have to bore your engine to gain power. You can only go from 348-366cc with the stock cylinder, so I have heard that only adds like 1 HP. Your power will be gained from the higher compression. 11:1 compression is as high as you can go and still run on pump gas. JE makes a 12:1 but that requires race fuel, and 93 octane is high $ enough! That why I recommended the JE 10.5:1 piston. You can get the whole kit for $200. You can check Webcamshafts.com or dirtdeals.com (World Class) for a Webcam.

As far as changing the crank, you can check fourstroketech.net for a 446 big bore and +10mm stroked crank, but now you're talking big bucks. I have one in mine but it really isn't worth spending $1500 on a Warrior to do this mod.

 

I'd listen to Raptor450 if I was you. Great advice!

 

Thanks alot guys now i just need to see how much i'm getting back for my taxes and figure out how much i really need to spend on my toys lol

 

The only JE 10.5:1 piston kit i can find requires me to bore 2mm. Am i just looking in the wrong spot or is this right?