I am starting to race this year. I was thinking of getting a big bore kit. I was wondering what size I schould get and from what company. Please help.

 

What type engine is it, 4 stroke or 2 stroke? Is it a 250R, 300ex, 400ex? This info would help answer your vague question.

 

It is a 300EX.

 

What kind of mods do you have now?

I race a 00' 300EX. Here are my engine mods:
TC Racing piston, cam, valve springs, and CDI.
WhiteBrothers complete exhaust system(E-series and header)PowerFilter, and 8-1 inch holes in airbox lid.
14 tooth front sprocket.
Ported and Polished head.

I would recommend getting some suspension too. The stock setup is great, but will start to fade when pushed on the track.

I would look to a big bore kit as your last power-up option. Your engine just will not last.

Chris 00' red rocket

 

The only stuff I've done to my engine enclude KN filter, White Brothers complete pro-meg exhaust, And spltfire spark plug. Also have Lonestar Racing a-arms +2"w,+1"f, swingarm, bearing carrier, axel, Graydon nerfs and bumper, Renthal bars and rear sprocket, maier plastic, holeshot xct tires, and Works shocks.

 

Next I would recommend a piston-cam combo, with CDI mods. With that WB exhaust system you have. This will really make her scream.

Chris 00' red rocket

 

Thanks for the information. Would TC be a good choice for piston cam combo and CDI. Tanks.

 

That's your choice. TC is not the cheapest, but they built quality products that will last. For a TC Racing piston, cam, valve springs and CDI mods. You are looking at $400. But Tom will stand behind his product if there are any problems. I highly recommend TC.

Adding these mods will make your EX a screamer. My ride will walk all over any Blaster, Warrior, Mojave or Polaris quad. I can even hang will mild 400EX's and 250r's.(and I have reverse)

Get what you want and don't let anyone tell you different. It's your ride, so it's up too you make her scream.

Chris 00' red rocket