All my buddies just got new 450trx's and I cant keep up any more.
looking for more power but I dont know where to get it.
big bore? hot cam? re-jet carbs?
only mod is work shocks and white bros pipe.
HELP!

 

get a 450r... and is it a slip on or full .. if its a full pipe you should've already jetted it

 

unfoutunately a 450 is out of the price rang.
its a slip on.

 

Airbox lid still on???? Free flowing air filter (I recommend ProDesign foam)??? Header??? And...of course a rejet.

The quickest, easiest way to gain top speed is to raise the gearing. This will however leave you with less low end (less torque!), so you will be slower off he line and have less power for hill climbs. This might be an option if you mostly ride open country and not so much tight or technical trails.

If you want more torque (low end power) and want to be quick off the line, then lower the gearing. This is a good idea if you are mostly a tight trail rider.

The trick is to getting both: Low end pwoer and top end speed.....not usually easy to do........

 

i did build a custom air box from perforated aluminum and stuffed a k&N on it. 90% of the riding I do is technical desert courses and working on jumps but it doesnt seem to want to accelerate up hill, like a large ditch or a dam.
what knowledge do you have of the 440 kit and hot cam?

 

I ride the 450R exclusively in the open desert. Even though I could ride down washes at 100 mph, I choose to gear down and lose some top end in order to get more explosive acceleration.

 

<div class="FTQUOTE"><begin quote>Originally posted by: huevon

i did build a custom air box from perforated aluminum and stuffed a k&N on it. 90% of the riding I do is technical desert courses and working on jumps but it doesnt seem to want to accelerate up hill, like a large ditch or a dam.

what knowledge do you have of the 440 kit and hot cam?</end quote></div>


If you have done these mods, and have a slip on. have you rejetted? with those mods it will be absoulutely necessary to rejet. Otherwise you will encounter all sorts of top end performace problems. Similar to what you describe about not being able to accelerate up hills.

 

Power:weight ratio

I'm 200 pounds right now and I'm going to the gym to get down to 170 or something so I have a better power:weight ratio. My buddy's got a 450 and he's like 150 pounds

 

<div class="FTQUOTE"><begin quote>Originally posted by: reconranger

I ride the 450R exclusively in the open desert. Even though I could ride down washes at 100 mph, I choose to gear down and lose some top end in order to get more explosive acceleration.</end quote></div>

you only get better acceleration in 1st gear, the other gears will just feel like you're in a lower gear.

if you gear up for a higher top speed, you dont lose any acceleration as long as you think of it this way: your 1st gear is now as fast as a stock 2nd gear, 2nd gear feels like stock 3rd gear, your 3rd gear is now as fast as a stock 4th gear, your 4th gear is now as fast as a stock fifth gear, fifth gear- well, just imagine going wideopen 5th, and then being able to shift again for another 5-10mph in top speed

MY point is, if you gear up enough, it will feel like you're doing 2nd gear launches all the time... if you feel comfortable doing 2nd gear launches all the time and think the acceleration is still good enough, just gear up taller and go filter, no lid, rejet, and fmf powerbomb header.

I bet hat if you geared up to make your 1st gear as fast as a stock 2nd gear, and you had a friend launch in 2nd gear, you would be completely even until he hits 5th and then you will slowly accelerate away.

How tight are those trails that you go on that you would regear for? whats your avg speed? my avg speed on my trails is 10-15mph... i dont know how hard it is to maneuver a 400ex through something that slow and tight, but a crf250r has no problem, you just have to work the clutch and have some skill [img]i/expressions/face-icon-small-tongue.gif[/img]

 

I suggest a header, jet kit, cam, and new sprocket ( depending if you want low or top end). Mine will keep close but not out run the r.