XR400 cam review

[RAPTORAZ]

I put a XR cam in my 2000 400EX today. My previous mods are: White Bros. E-series silencer(18 discs), airfilter, rev box, no airbox lid, 45 pilot, needle moved up one notch, Splitfire TP plug, and a 168 main. All I can say is WOW! The bike gained a lot more power than I thought it would. It's the best mod I've done to it so far. It has way more mid and top now. Just thought I'd give my opinion on a common topic here.

[Nausty]

thanks I have been woundering a lot of this cam because of the fact that its a drop in and I don't need re surfaced rockers and its cheap compared to others. I was woundering though is if you did it your self and if so how hard was it and do you think someone with basic engine experience could do it?

What did it do to the bottom end. Is it the same, worse,better?
I'm thinking about getting one but I realy like the low to mid for woods riding.

[Nausty]

I think it would lose some low end but it depends do you ride more in the 1/4 thottle range or the half throttle range?

Since I don't have all the motor mods you rich types got, I tend to spend my time in the WFO range. Just the same, I'm considering the XR cam and would be interested in the effect on the low end.

[Nausty]

I think basicly there is no bad cam and that they are meant to put the power in differant rpm levels where people like to ride them and maybe more aggressive. So if you like to lug around and use the torque than you should get a cam for low to mid power or if you ride wide open a lot you should have a mx type cam am I right?

[RAPTORAZ]

I had a friend at work install it. I bought him a GT Thunder cam in exchange for his XR cam with installation. I figured that since he had already done a cam and 440 kit in his that he'd be better at doing mine. As for the installation process, if you can adjust your own valves than you can put in your own cam. It was a piece of cake. He took his time and the whole job only took about an hour. I didn't notice any loss of low end power. But I didn't "lug" the motor around either on it's test run. I was too interested in the new top end pull it had. I still can't believe what a difference it made. Bring on the Z400!

[400exdad]

I was told that with the XR400 cam, a higher compression piston was really needed to recover the loss of low end. I'm basically pretty cheap when it comes to tearing into a almost new motor and replacing a piston. So, if I don't loose too much on the bottom (I'm running 13T) I would probably be okay with just the cam change??? My b-day is next week and the cam would be a cool thing to get!! :D Has anybody done many of these without the piston? I want more power, like mid-range, but I'm not always on tilt in the RPM's. Am I confused or what?:huh :D

[Taco]

I think blackguyona400 did his xr400 cam first might wanna get his opinion

Yeah blackguyona400 added just the cam so PM him about it. I also did not notice ANY loss in the bottom end,,but I also added a high comp piston with the cam,,I don't think you'd loose any more bottom end compared to a stock 400ex cam your just adding more to the mid and top. All I can say is it's cheaper to add a new piston and cam than a new complete exhuast system,,and the cam/piston combo adds ton's of power compared to the exhaust..

[Blackguywithouta400]

1st K&N and rejet no air box cover - Gave me more top end and little more throttle response.

2nd DMC Exhaust rejet - Gave me a lot more torque improved on everything I had before very happy with motor now.

3rd XR 400 Cam Rejet - With pipe and K&N improved my bottom end way more and had the biggest hit around top end of second shifting to 3rd. Made 3rd gear my wheelie gear because 1&2 came up to fast. Motor didn’t rev as fast as I thought I would this combination had me holeshoting raptors threw 3rd into 4th on the racetrack.

This is all with a stock bore and Carburetor

4th Lost my mind 11:1:1 425 88mm piston with ported head
Now the bike revs real fast can do 5th gear wheelies all with stock gearing and tires it has torque but in the upper gears it can keep the front down and just move forward im sure I will be racing Raptors soon and will find out how fast it really is.

Hope that helped, I would advice this cam to anyone I like to work on my quad all the time (helps not being married) so im going to later this summer get the HRC cam just to try that out I think ill keep both the XR & HRC to compare the two. I think I got the most out of the cam after going to the piston but you see a large difference on a stock bore. I have my local dealer stocking them now because everyone wants one. Its easy to install and worth the money. If your like me and can never save up to do it all at one time buy it piece by piece then you will combine all your mods and you wont have a bike that u don’t know how to ride because the power is just up top or way low. My goal was to build a motor that would have a very large power band so when I shift I never fall out of the power, since its to expensive to change the transmission ratio. Wide power is good and safe, its what makes the 400 the 400 because its predicable.

When you are talking about the XR cam, are you talking about the stock XR-400 cam or the HRC power up can? The reason I'm asking is because of the big difference in price between the two.

[400exdad]

quad a1... we're talking about the stock XR400 ($120 :cool: ) cam, not the HRC cam.

Thanks guys! I think I'll call Marcums today for the cam.

:square <<< Me without ExRiders!

Originally posted by 400exdad
quad a1... we're talking about the stock XR400 cam, not the HRC cam.

Thanks guys! I think I'll call Marcums today for the cam. EXriders is great!!

Make sure to have your wife pay for it since it's a birthday present..:D

[Dave400ex]

Blackguyona400, Rico, how much HP do you think you guys have? With all this talk about just getting a Cam, I am thinking about getting the TC XC Cam and Viton Valve Seals soon. Then I would have awesome Bottom End. What do you guys think? I`m either saving for PEP ZPS Shocks, which would be nice to have, or I will get the Cam and stuff. Which one should I do?


For all you guys that want Bottom End, I would get the TC XC Cam. It`s built for all Bottom End.

With the cam alone I wouldn't know the HP increase....I'm guessin with the complete setup I have it would be in the high 30's..

[Dave400ex]

Rico, I wanted to know how much HP you think you have with all your Mods.

[Blackguywithouta400]

BMX TIRES xr 50 cam man thats funny

2001 400ex W/bearded fenders, plastic flywheel, paper airbox. Extended Fisher Price Racing A-arms, Red Rubber Brake Lines. Tonka case saver, Rubberband steering dampner, perch for the parrot & lever 2000, Used E-brake blockoff, Rubbermaid axlenut. Auqu header, Mopar powercore, Wooden handle bars. Paperclip racing handlebar clamp, pantyhose headlight covers, & paper number plates. AC/DC racing front bumper, fiberglass swingarm skid, full body wine dispencer, & propeller nerfs. Sponge for air filter, black neoprene hood cover. Ceramic eliminator axle. Dimsum triple rate shocks W/rezzy, Tupperware black gas tank cover, stripped wire kill switch & ammco power shifter, Sandpaper seat cover, Styrofoam resevior cover, Gas petrock, Rear master bater guard, seat launch & head cover, Chrome tires and rear brake pedestal, Custom oil retainer scoops, Tyson hand guards, Dynomite kit, XR50 cam, JE 16 piston(1.8:1), Douglas Fir .19 race rims W/knockoffs, hole**** BMX tires all around

Laughing my as off

[400exJOE]

hey rico, love the new signature! LMAO! I checked the rubbermaid site and I couldn't find any of those 400ex parts. Maybe you have the link? Thanks:D

[Dave400ex]

Rico, that is Funny. Where do you come up with this Stuff? LOL.

[kabd69667]

Rico, not to doubt your high aray of knowledge or anything, but a 440 with a cam and piston only puts out about 40. Thats what GT Thunder says and CT's website. I would say a 416 with 11 to 1 and a cam would be about 34 or 36. I maybe wrong but thats just what i think

[Clay]

Kabd69667,
Not to question your knowledge, but wouldn't 36 be in the high thirtys.:grr

[kabd69667]

well i consider 30-33 low, 34-36 mid, and 37-40 high...thats just my opinion though man. No flame intended:grr

[Clay]

LOL, i wasn't flamin either, just pickin at ya a little, LOL:blah :D

[kabd69667]

haha, i was gettin worried there for a minute

[Dave400ex]

34 HP would be a good Gain.

[patrick delao]

I talked to Mike a Harry at Trinity and he said a Rec or play 440 like mine would be around 43hp without a bigger carb. I have a 440 kit 11 to 1 piston XR headgasket .025 thick, XR cam, cam degreed 4 degrees, 4 degrees flywheel key,5 angle valve job with play porting,FMF p/c 4 with power bomb header and K&N filter with no lid and 101 trick fuel. I think Rico would have to be at the HIGH 30s 38 or so :)

[Dave400ex]

If I got a TC 416 Kit, 35-39 HP would be enough for me.