I have a 1993 Yamaha Warrior 350, i am looking at pistons to get and i have looked at wiseco and JE. Wiseco has a piston with a bore size of 84mm and 11:1 Compression for $165.10. Je has a piston with a bore size of 85mm and a 12:1 Compression for $197.09. The original bore size is 83mm and i believe the original compression is 10:1. i am pretty sure that nothing has been done to the engine. I am looking for more power and i was wondering what would you suggest for me to get or is there another good quality piston out there that would be better then those two?, i am not concerned on price. and if i were to put a new piston in what else should i do like vales or timing chain or camshaft etc, or would it be fine if i just did the piston? and if i did the vales are there some aftermarket vales that are better than the stock ones? oh and my carburetor cracked and it now leaks gas so i was wondering if you know of a place that would sell a carb for the 1993 yamaha warrior. i looked at the stock carb and that is 400$ so thats not going to happen, i would build my own carb before i bought that.

oh and don't say "save your money for another bike" or "Don't put all this money into this bike or anything similar to don't do this. i am just looking for answers for my questions.

Thank You.

 

The JE is better because it is lighter weight than the Wiseco, which will help the engine rev faster. Here is a link to what I would recommend: 222085 Product Detail Information - JE Pistons. If you go over 11.5:1 compression you have to run race fuel - not a good idea for a trail bike. If you haven't done so already, a good exhaust like HMF would be a good place to start. On the Warrior there is no need to buy the full exhaust, all you need is the slip-on. The Warrior's head pipe is already oversized from the factory so you will not gain any performance with an aftermarket headpipe. Then a good filter like a UNI or K&N, and jet the carb while you're working on it. These mods should allow you to up the front sprocket 1 tooth if it hasn't been done already.

A cam will really wake that engine up better than a piston by itself. I recommend the Webcam .430" 84 grind($153) :http://www.webcamshafts.com/index_bl...le_search.html. This requires a core to send in and requires heavy duty valve springs ($100). You can also get oversize (+1mm) valves from Kibblewhite, that would require a machine shop to do some grinding on your head ($50+). Also a good port job ($250+) would help make it faster. I had all of this done on my Warrior and it would run with slightly modified 400EX's.