Need some advice on bore kits?

[youngin]

Okay i got a 02' 400ex with full Big Gun exhaust, jet kit, and stage II hot cam.. I'm wanting more power. I havent installed the rev box yet, cause im trying to decide with what bore kit i should go with.. I do alot of hard trail riding and ride alot on the motorcross track we built on my land.. I want something dependable and reliable. Please do not tell me to buy a 450r. I need some good (Mature) advice.. I'm not looking to out run anybody..I just want some more grunt..

[JRDrider22]

so get a 440 big bore kit. and maybe a lectron or another carb as well for some more power

[youngin]

Yeah but, i thought they said that the 440 kits werent very good??

[JRDrider22]

theyre a lot better than stock motor. my 440 rips but i also have a rev box and a carb. with little progress on each part you want to put on your bike will rip. i love the 440 kit.

[400-416EX]

Youngin check your in box

[cals400ex]

oh, you don't need a 450r. just buy a yfz. :D just kidding


i think you will be happy with a regular 416. you will want a cam, pipe, and jetting too. after that there are a few other mods to do such as lightening the flywheel, aftermarket carb, porting/polishing, etc

[deathman53]

I would say, get it ported/polished, cam, exhaust and front shocks(I know its not a motor item, but a huge help with riding), don't believe all this stuff about getting a big bore without the cam, carb, pipe, etc and it being really powerfull, your power is make in the head, cam, and exhaust.

[youngin]

Is no one reading my question???lol I already have the cam exhaust and jet kit.. Im looking into investing into a aftermarket carb, but just what a reliable machine..

[bradley300]

it should be very reliable, just keep the compression on the low side, like maybe 11:1 or so and you should be fine. also change your oil and filter and keep your air filter clean