400ex cam and pipe decision

[JACK STRAW]

a local kid is asking me what cam to put in his '04 400. it has no upgrades. he doesn't race just trying to keep up with some faster bikes. input on pipe and cam. thanks

[KKiowaTJ]

If its 100% stock, Putting the correct jets in it will make a difference. Id shoot for a slip-on, UNI and dialed in jetting. That and if hes trying to keep up with 450's, Better off getting one than dumping money trying to run them down. If they are of the same cc, Id go for the slip on and filter, Then dial it in. Just my opinion though, If I had to pick a cam, Id stick with Honda and go XR400 cam.

[LxMxL97]

I would go with a stage 2 hotcam due to the fact that you can use the stock rocker arms and as far as an exhaust I like my fmf powercore 4 with the power bomb header

[cheater13]

Definitely stage 2 Hotcam for what you want. That's what I have in now and I'll be switching to a custom Webb cam when I ship my engine off in a few weeks.

[2001400exrida]

stage 2 hotcam and never look back. it is the number 1 cheapest and most noticable mod. I think they're around $150 if i'm not mistaken. no other mod will get you the power you will get from a s2hotcam at such a cheap price.

a s2hc, pipe, and lid off with proper jetting is a very good start to a thumpy 400.

[LxMxL97]

stage 2 hotcam and never look back. it is the number 1 cheapest and most noticable mod. I think they're around $150 if i'm not mistaken. no other mod will get you the power you will get from a s2hotcam at such a cheap price.

a s2hc, pipe, and lid off with proper jetting is a very good start to a thumpy 400.

I agree completely except the lid if he was in the dunes go for it but if he's in the woods where it's really muddy I would keep it

[KKiowaTJ]

I really need to open mine up and find out whats just in it. All that I know, Is a pipe and filter, But can hang with a built 416 with the S2 hot cam and that was when I was 220 and he was 170 on a fat bloated day. I hope its stock so I can go the XR route, But I have a feeling its a tired, Worn out 416.

[RNL]

I have always been steered to the stage one Hotcam on a 400ex if you have the stock piston and compression ratio. Curious on how you guys did with the stage 2 cam? Either way, to the original poster, yes a slip on and properly dialed in jetting is the place to start, and a cam for more/better results. Just make sure whatever is done, have the jetting spot on.

[chronicsmoke]

When I put a cam in my 426 a few years ago I found a brand new Magnum 2 cam for like $85 new on ebay.. there were some mixed reviews and some people said it was a drop in cam while others said it needed supporting mods to run it..

Been running strong as a drop in cam and really woke up the top end. Night and day difference with the BB kit that's in it.

[DragonGunner]

I have always been steered to the stage one Hotcam on a 400ex if you have the stock piston and compression ratio. Curious on how you guys did with the stage 2 cam? Either way, to the original poster, yes a slip on and properly dialed in jetting is the place to start, and a cam for more/better results. Just make sure whatever is done, have the jetting spot on.


I agree....I think the stage 2 is too much for stock compression....I think the guys that got the stage 2 have 11:1 compression.

[RNL]

I agree....I think the stage 2 is too much for stock compression....I think the guys that got the stage 2 have 11:1 compression.

Good to see I'm not alone on this. Not saying you can't run a stage 2, but with a stock piston and compression I'd do a stage one. John from Venom gave me this advice years back, he knows his stuff pretty good.

[MtnEX]

I don't know on the cam. I have been trying to weigh that one out... and I have also been trying to decide on my side of things rather or not my perception will be different on the cam results being that I have a 450 too.

Main reason I bring that up is that I think I would skew the suggestions more towards those who have a stock engine over those who are bored or stroked or do a way different type of riding.... as it is about what type of change from where it is to where it is going can be absorbed.

I will give a real good example from my experience. I didn't make my choice actually. I took it somewhere and said here, install me an exhaust and filter and jets that will work real good. What I got it back with was a full Yoshimura exhaust, an air filter I not worthy of wearing to mow the yard and some jets. I was highly dissappointed in the results because prior to that I had owned 2 strokes that responded much better to mods such as this, and a Warrior that was a major build all at once.

Seemed to me I gained extremely little for what I paid and that I actually did more "moving" WHERE the power was than anything else. Seemed to loose a little low end in trade for additional peak and top end. Sounded amazing, one of the sweetest sounds I can think of, but I was really unhappy.

Fast forward though. Now that I am running a 450 and have gotten adjusted to a much higher strung motor, when I get on the 400 again I don't notice the low end grunt subtraction but do notice the top end addition.

In any event, I would suggest ANY slip on muffler and cleaning up the header welds. The 400 seems to like this pretty good, maybe even better when the motor is still fairly stock. Now I should probably port my head, bump up my compression and install a stage 2 or stage 3 cam? And I would probably be more accepting of how that will perform than I would have been if I went to that without ever getting the 450. Hope that makes sense. Just trying to give a parallel example to make you consider what people have done to their bike as they give exhaust and cam suggestions.

[2001400exrida]

Good to see I'm not alone on this. Not saying you can't run a stage 2, but with a stock piston and compression I'd do a stage one. John from Venom gave me this advice years back, he knows his stuff pretty good.
I've never run a stage 2 on stock compression, but my friend has one with a fmf powerbomb and stock motor. He loves it and it rips pretty good too. John doesn't do much work on the 400ex's so I don't know how far his knowledge goes with those motors. He did the port work on my 450r and highly recommended the s2 with the mods i'm running. the hotcams are drop in cams and they are just fine for a stock 400ex motor. The thing about the stage 1 that I did not like when i had it in my 400ex is that it really drops off at the top rpm's. I ran the stage one and it will tear your arms off in the woods so it's got tons of low end, but you really feel it start to plateau when you get to the higher revs.

raising the compression will give you more benefits of any cam of course, so if you do want to really take advantage of any cam, you should jump up a little on compression.

[RNL]

I've never run a stage 2 on stock compression, but my friend has one with a fmf powerbomb and stock motor. He loves it and it rips pretty good too. John doesn't do much work on the 400ex's so I don't know how far his knowledge goes with those motors. He did the port work on my 450r and highly recommended the s2 with the mods i'm running. the hotcams are drop in cams and they are just fine for a stock 400ex motor. The thing about the stage 1 that I did not like when i had it in my 400ex is that it really drops off at the top rpm's. I ran the stage one and it will tear your arms off in the woods so it's got tons of low end, but you really feel it start to plateau when you get to the higher revs.

raising the compression will give you more benefits of any cam of course, so if you do want to really take advantage of any cam, you should jump up a little on compression.

John did 400ex work before the 450 era. He told me did 3 400exs that we're his personal machines as well. His best mods according to him we're the stage one cam, slip on and a higher compression piston. Keep in mind he lives in the same state as me so our riding styles might be different than other people on here. If you look at the specs, the stage one cam still offers increased performance on the top end over stock, just not as good as a stage 2. I think cam choice needs to revolve around where you ride, but also how you ride. I wish there could be a test of two machines side by side with equal mods and the two cams, that would be neat.