416/440 big bore kit vs. high comp piston/cam

[HondaChris]

I am looking into options to get going in the next few months. I am toying with the idea of either a 416 or 440 bore kit, or a high compression piston and cam install. Any opinions/suggestions on any of these would be great. I'm looking to get the most bang for the buck, but want it to be done correctly, and keep reliability on my side.

[HondaChris]

I got sidetracked and hit submit before I was ready. What I was looking for also is what mod will do what as far as bottom end, mid range and top end. I dropped a front tooth on the front sprocket to get more bottom which I love, but am kind of missing the top it took away. Is any of these an option to keep the bottom end and go back up a tooth to stock, or vise-versa, give me the top end back and keep the 14 tooth on?

[cals400ex]

i would do a 416 for the reliability. you can put in a 10.8:1 compresssion piston in your bike with a cam. this will wake up your bike nicely.


the cam is what will gain your higher end performance. however, you can put a cam in that isn't really aggressive so you won't loose any bottomend power. yeah, take the 14 off if you want some top speed. an xr400 cam or a hotcam stage 1 will be nice for power gains everywhere. however, the stage 2 is what most people recommned because it opens up more up top. i run the stage 2 because i wanted top end power. for tight trails and such, i would have got the stage 1. you will have about as much bottom end power as stock even with the stage 2 but you just need to rev the bike out with that cam. the choice is yours. you can get a piston, cam, gaskets, and boring for under $400. just buy a service manual and install it yourself and your ready to go.

[Moded86R]

I have been wondering the same thing.I got a qoute from C&D and they said 120 for the 406 and the same price for the 416.The 406 was 10.5:1 compression and the 416 was 10.8:1 compression.I am also considering a 440.But I don't want to deal with the added heat from the big bore.I think I am going to go with the 406 and a HRC cam.Also thinking about trying to find a used head and have it ported and bigger valves put in.Not sure who will do that yet.I still need the $.I don't want it to be the fastest thing out there.But I am tired of it being the slowest!


Hoping this HMF slip on gets here so I can see how much it helps.Then I will probably decide which way to go.

[H_W]

I would recommend getting the 416 high comp kit with a good cam. I am contemplating getting a 416 or 426 kit for my 400. With my current mods, it is pretty fast in the mid range and on top end, but I want more bottom. After that, I am through spending money on the 400ex. I will be saving up for a 450r.

[Moded86R]

Thanks for the info H_W.


I am mainly looking for more torque than anything.Not to worried about top-end.I would like to get corner to corner faster and up those steep hill climbs a gear higher.

I just don't like the idea of a bike taking a motor that runs perfect all apart and boring it .080 over.I believe there is one more bore after this right?I have pretty much decided on the HRC cam.I like the idea of it being a honda part.Depending on how this new job goes you never know I might go with a 440 with all the goodies.I have witnessed a few that really haul the mail.But then again I like the fact that this thing starts everytime.

[HondaChris]

So if I read this right, the stage 1 cam would give me a little more from the bottom to the top, and the stage 2 would give me more on top? Is it a noticeable enough difference with the stage 1 that I'd be able to go back up on the front sprocket and be close to what it was with the 14? I ride a little bit of everything. We have 2 play mx-style tracks we ride on, plus trails in our woods, and public trails up north, and Silver Lake dunes to boot. I am wanting to do something that would run a bit stronger in most, or all if possible in these areas.
What would be a good choice for manufacturer of cam, that I can keep the stock rockers and springs?
How much of a difference does a stock bore high compression piston add? Is it worth doing or should I go with the 416 bore if I'm going to go with a high compression?