450r motor rebuild

[hunter61]

I've got a 2007 Honda 450er fox/houser all way around, the motor is bone stock with a hmf full exhaust and k&n oversized filter, I'm moving up next year to b class, and was wondering what would be the best to do to the motor for power & reliability. It's my only bike,
Thanks!

[Scro]

A cam is usually the first mod that most people do. It reliable power as long as you go with a drop-in, and a fairly easy install. It really makes a difference on these motors, too.

[eastside 400]

put a piston in, if you wanna run race gas then go 14:1 or 12.5:1 if you wanna stay pump gas. Then a stg 2 hotcam. thats all you really have to do to the 06+ motors esp for B class

[hunter61]

Alright thanks, the top end will have
To be rebuilt. What about a piston or head work? Downfalls?

[hunter61]

Thanks, I've heard ignitions add hp?
And sending the carb off and getting it bored does too?

[hondarider421]

this is a full list of mods to do for power
exhaust
fuel customs intake
dirtbike top end
piston
and thats a go the dirt bike top end on these bikes help alot the valves are bigger and the heads flow alot better the cam in the dirt bike is the same as doin a hrc kit and the fuel customs helps alot piston grade depends on wat gas u wanna run but thats a lil expensive list but makes great power and fun to have i know i run it

[Kovatch]

To be competitive in B Class:
12.5:1 piston - CP piston 13.5 would be nice, but you want reliable

Stage 1 or 2 cams, replace and or upgrade valve springs if you replace the cams. Just good to start fresh. Stage 2 may require stiffer springs

FCI intake will add another hp

Tokyomods ignition

Port work won't hurt your reliability, it will definitely help with a piston and cam...

Those should keep you running strong.

[Balaz_73*00]

I was able to pull pretty decent starts in B class at nationals. I have a 13.1 piston, 02 crf cam, full exhaust, and a port job. Stock 05 carb too which I know was prolly holding me back. But with that you'll be just fine

[400exmxrider15]

try the green wire mod, that adds 1000rpm...

[400exrider707]

Somethings never change. Still people offering advice on subjects they clearly know very little about.

A cam/piston combo would be a great start. Your compression ratio will determine whether or not you're going to have to run race gas, so are you willing to spend the extra on race gas? let us know and we can recommend a good combo here for that.

Porting is a GREAT way to add power... did someone seriously say it will lose reliability? I can't wait to hear the explanation on that one...

We need to know what kind of budget you're working with too.

[Kovatch]

Who said it will hurt reliability?

[Ruf Racing]

Originally posted by Kovatch
Who said it will hurt reliability?

^^ x2 ^^

Some pretty good advice, so far. :macho

[hunter61]

Thanks for all the advice so far. Money really isn't going to matter, cause it's the off season, I want to get power without having to build the motor up alot! Race gas, would really would like to run pump gas because I ride alot. Any suggestions are welcome!
Thanks!

[hondarider421]

Agin man a 02 or newer dirt bike head and rering ur piston and ull be ok then the exhaust if u dot have one and ull make good power the dirtbike top end only works on 06 and newer so noone with a 05 should try it