400EX Project need some help!!!

[ride red]

I have a 2000 400EX with a JE 11:1 piston, WB race cam and rev box right now. I do alot of drag racing around were I live. Over this winter coming I want to do some more stuff to my 400EX to give me some more ponies. We race with 250r and everything they don't have different classes so it kinda makes it hard for us but I was thinking of doing this stuff and let me know what you think and if it would help me gain more HP. I'm looking at the Curtis Sparks X-6 pipe to replace my Yoshi slip on, and a keihn 41 or 39 carb not sure which one, any suggestions?? I'm also thinking of sending it out to someone and get it ported and polished but I'm not sure who to send it to to get this done. Who would be a good place to do this?Also if anyone has any other suggestions on something I could do please let me know.....thanks

[ride red]

Anyone have any suggestions at all??????????????

Well, since you insist on suggestions. You didn't say whether you had modified the airbox or changed air filters, so I would go to an aftermarket filter and drill holes in the airbox lid (I prefer drilling holes over completely removing the lid). K&N filters flow the most air and therefore give the most power, but foam filters are better at stopping dust from entering the motor. I would prefer the Sparks pipe over the Yoshi slip-on, but for stock or slightly modified motors (which is what I would consider yours at this point) I prefer the TC slip-on over both. The porting would help somewhat, but be careful with "full race porting" and such, because you can lose quite a bit of bottom end if you're not careful. Any of the reputable motor builders should do a good job with porting, just call and talk to them. Tell them what you are using the quad for and what your current setup is, if they suggest something then I would do what they suggest; because they do it for a living and they know what they are talking about. For good bottom-end the stock 400 carb is pretty good. For more mid-range and top-end you could use either the 39mm or 41mm Keihin FCR carbs, basically whichever you like the idea of better; I don't think there's that much difference between the two sizes for most motors and uses.

The next step up after the porting and carb would be a big-bore kit. If you plan on going to a big-bore later on, then the complete Sparks exhaust would be my choice because you may want higher flowing headpipes for better top-end with the larger motor.

[MX MadMann]

the TC slip on looks like a joke to me. all that money for an alluminum dixie cup? i think the sparks is a waaaaay better system and its been proven over and over. the FCR39 should be plenty of carburator for a 400ex unless its on alky or a really big motor. you might want to look into a timing advance key as well.

[ride red]

I do have a k&N air filter on my 400ex I forgot to list it. If I would go with the port and polish, X-6 pipe, maybe a carb and a 416 bore would I be able to compete with the R and banshees or am I still not?

[honda250]

k ill skip the basic mods, the obvious, but i would keep the yoshi if its a full system. but bore it out to a 426 or a 440 but 426 would be better even though it wont be as much of a gain.higher comp psiton. www.thunderproducts.com the have a dial a jet. it $110 it adds hp and its easy to do , i am orderin it now for my raptor. it adds fuel efficiency but i doubt your worried about that. but better throttle repsonse. and it stop u from messin with jets, it does it for you some how. other mods umm lets see have u messed with your sprokets , that would help with smaller front and rear for accel gains. what size rear tires r u running?

STROKE IT!!! put a 465 or 493 or any of those other big displacement kits in it. Call For Dirt Only @740-967-1078. He does some great all out HP porting. Quick turn around good price reliable. and he loves making them big.