Best mods without big bore? (FCR,X-6,HRC)

[the-ex-files]

I currently have an 03 400EX with a Sparks X-6 pipe and Uni filter. I was looking into doing more mods, but I don't want to do a big bore, until the motor takes a crap. I was thinking about adding a FCR39 carb,HRC cam, 16 tooth sprocket and Sparks advanced timing key. My goal is to get more of a top end hit. I did a lot of searches, and found that the FCR 39 is the best carb, and the HRC cam is real good too because it's a "drop in" cam. What do you guys think, would this be a pretty good increase or just go big bore? Thanks for any replies.

[wilkin250r]

The best mod you can do is high-compression and a cam. At this point, some people prefer to bore out to 416 or 426, other people want to save their overbores, so they go stock or 406. But regardless if you bore it out or not, the best mod you can to is high compression and camshaft, hands down.

[EXDUNER127]

Or depending on who your engine builder is...before you get the cam, get the carb, timing key and get a port n polished head, and you will get a nice increase. opening up the head in the 400ex is more power than people think, my engine builder got 4 hp out of my head. I run right there with my friend who put the cam and piston in his bike(416). so then when you want to rebuild you can add the cam and piston and already have the carb and port job, because the cam isnt going to work its best with out opening up the head.

[wilkin250r]

If you are low on money, that may be an issue, but I don't see the point in spending $250+ porting the head, and not also spend a few extra bucks and get the cam at the same time. You have to take the cam out to do the headwork, you may as well save the effort in the long run.

Would you buy new rims for your car, and keep the same tires, only to get new tires a month later? You have to take the tires off all over again! :huh

[EXDUNER127]

Yah thats a good point....how much are the HRC cams anyway?

[brianC400X]

Your best bet price per performance in a drop in cam in a hotcams cam. They have 3 different powerbands to choose from to my knowlege. Stage 1, 2, and 3.
Stage one comes in on the bottom end and pulls hard through the midrange with slightly more top end than a stocker. Stage 2 comes in at the midrange with even more top end than a stocker. I havnt ridden a stage 3 but one can assume that they come in even higher in the RPM range and are all about top end. Anyone rode a stage 3 hotcams eqipped 400ex feel free to correct me. I have a stage 1 myself and am very happy. One might assume that the stage 2 would be better for sand but the off idle throttle response is a great advantage. One that has you off the bike lifting your back tires out of the holes thry dug less often. Also Sparks timing advance key($15 from C&D racing) gives even better throttle response. Its the mod everybody who doesnt have a wild big bore should do. The best 15 bucks I have put into my motor yet. Keep in mind you wont be dissatisfied with your cam change no matter what you choose.

[cals400ex]

the hrc's are a good $270.

i also say get the cam and piston. i only have a 406 with stage 2 hotcam and it really woke up my bike. i had a fcr 39 and i wouldn't waste your money. you gain a lot of throttle response which makes you feel like you gained a ton of power. in reality, you don't gain tons of power. on a track it is nice but for dragging, not too much will be gained. on my 406 i gained about 1 bike length from a stop thru 5th gear. also, the x-6 doesn't perform as good as the x-4 on my bike. just something to consider...

[EXDUNER127]

When i put on my fcr the dyno ( my buddy owns his own shop) i gained 3hp plus throttle response sometimes and then when i ported the head i recvd another 3-4hp(depending how i dial it in)
and when my friend put a 416 in his he got 5hp when tuned. my friend (engine builder) told him he wasnt going to get the true performance out of the 416 without a carb and ported head...
so what i trying to say you can start in what ever direction you want, as soon as i get a extended swing-arm i will put in my cam and piston so i can keep the front down at the dunes!:D

[cals400ex]

yeah, possibly my problem is that i am running the stock head. i plan on doing some porting but i would like to find some titanium valves. however, i can't seem to find them...........

[EXDUNER127]

Hey cal, when you do your valves you should just do oversized valves, you will notice a nice differance with that mod when you port the head. I am doing it when i add my cam and piston!

[cals400ex]

i haven't talked to many people who have had great success with oversized valves. are you just going 1mm over on the intake or what are your plans?

[the-ex-files]

So it's possible to put in a high compression piston without boring? Can anybody recommend a good piston that will fit in the stock engine? Thanks.

[04'400ex'er]

I think 10.8-1 is the highest you can do on stock bore. I would do that, a HRC cam( I dont think hotcams make stage 3 for 400ex), FCR 39, Sparks Port and Polish job, X6 pipe, K&N filter(flows better than Uni but dosnt filter as well) and outerwears, and rejet. That's close to the best you could do without 416. then when your motor takes a poop, All you'll need is to bore the sleave and get a new piston. ;)

[PHIL_B54]

I went with a stock bore 11:1 wiseco piston and a drop in cam, and i am very happy with the results.

[brianC400X]

hotcams does make a stage 3 for a 400ex my neighbor has one

[EXDUNER127]

hotcams does make a stage 3 for a 400ex my neighbor has one :huh

dude your friend doesnt know what he is talking about, hotcams doesnt make a stg 3 for any of there bikes. go check out there wesite www.hotcamsinc.com (http://www.hotcamsinc.com)

he probably has a stg 2, not three!:rolleyes:

[brianC400X]

He always told me stage 3. Ive never been to the hotcams website till today. I emailed them and asked if they ever made a stage 3 at one point just to make sure.

[EXDUNER127]

Yah because every one that builds cams, (most) usually build 2 two cams, one for bottom to mid and another for mid to top. or even all around cams one mild and one full race like sparks! I dont know what a stage 3 would be. Maybe just more top end!:)

[the-ex-files]

OK. Thanks for the info guys. I learned much.