building 416ex motor

[cory gubser]

I am building my 400ex. so far i have 416 bore,11 to 1 Je piston, stage 2 hotcam, fmf power core 4,xr 400 head gasket, kn filter, 3 1 inch air vents in air box lid, 160 main jet, 42 pilot jet, base gasket removed.


It runs really good but i am still looking for more power. their is still a lot of options out their. I am looking into the 450 r carb but still looking for more info. Are they useing the 05 carb or the 06. I am also was woundering about the degree key. Anyone have any suggestions?

[400EX QUADER]

stock yfz 450 carb... which is a fcr 39mm. I have one forsale... they arent cheap but work well with modded 400's like yours...
thanx:D

[trx400exxracer]

get another carb and mabye a crf450(dirtbike) timing chain
mabye a port and polish
different pipe mabye a yoshimura full system

[FoxRacing81]

Originally posted by cory gubser
I am building my 400ex. so far i have 416 bore,11 to 1 Je piston, stage 2 hotcam, fmf power core 4,xr 400 head gasket, kn filter, 3 1 inch air vents in air box lid, 160 main jet, 42 pilot jet, base gasket removed.


It runs really good but i am still looking for more power. their is still a lot of options out their. I am looking into the 450 r carb but still looking for more info. Are they useing the 05 carb or the 06. I am also was woundering about the degree key. Anyone have any suggestions?


Get a 450r carb, Curtis Sparks full system pipe, CRF450 timing chain (just to be safe), Port and Polish, 3-Angle Valve job, and if I we're you, to be safe, I'd definatly get a new crank or atleast a trued and welded rod. Don't wanna have it let loose and end up paying even more $$.