450r motor upgrades

[RideRedRideHard]

I am looking to make some modifications on my motor to get some more power out of it. i already have a curtis sparks exhaust a k&n air filter, no air box lid and rejetted accordingly. I'm just wondering what other guys are doing to their 450r's to make them fun a little harder. I mainly ride in the trails but when i drag race i like to win. I've thought about big bore kits, running a different carberator (i hear the crf450r carb is a lot better and even running a 39mm kehin like the yfz450 seems to work good) and a hotcam stage 2 cam.... but i dont want to dump a lot of money into it and not have anything much better in the end. Any help would be much appreciated. Thanks

[29FTEX]

The FCR carb really doesn't add any power, just throttle response. It adds to the fun factor more than anything.

Staying with a stock bore motor is fine. Get a 13.5:1 stock bore piston. This requires race fuel.

Get a good cam. The better drop in cams are HRC and Hot Cams Stage 2. If you want a little more out of it, get the Johnson cam .400/.375 lift. It requires degreeing it in and more work than the drop ins.

Head work. Steve Polk at Pinit Motorsports is getting some big gains from a stock valve and stock bore motor. (831) 444-6309

[RideRedRideHard]

The throttle response isnt bad on it stock but it is a lot mellower power than the yfz450. i'm lookin for the extra throttle response. ive heard that edelbrock's carb is suppose to give the 450r good horsepower gains and i was thinking about going that route as well.

the only thing i have against going with the higher compression piston is a buddy of mine has a 440ex that had like a 14.5 compression piston and he kept pulling the head studs out of the jug. but there's a couple guys at my local honda dealer that have been runnin 14.5 compression pistons and havent had any problems with there 450r's.

wut else do i have to do if i have the head ported.... i've heard its hard to get them to run right after you do that. thanks for the info

[29FTEX]

No head stud problems on the 450R with high compression pistons. The 450R loves high compression pistons. There's always a limit though. The 13.5:1 will make you and your motor happy.

Get the Honda CRF 40mm carb, then you just need the adaptor. You'll find a lot more help getting that set up, and easier to tune.

Never heard of a bike not running right after a port job. Maybe because it wasn't jetted right for the changes. If you give Steve Polk a call, he can tell you what they offer on head porting.

13.5:1 Piston ~ $185
HRC or HC stage 2 cam ~ $115 - $130
CRF carb ready to bolt in ~$400
Head work ~ $250 - $750 (lots of different prices depending on your desires).
Get a good exhaust, a good intake system, and your set.

Later comes the CRF wiring conversion, and a few other go-fast goodies.