i have an 02 400 and i was riden it today and the topend went so i was wondering what kind of big bore kit to get and what kind of carb to get cuz if im gonna rebuild it im gonna go all out and make it a mx quad i already have a stage 1 hotcam e series full exhust and lonestar arms elka suspension and lonestar a arms but what is the best setup for mx

 

whoops i said lonesatr a arms twice my mistake

 

i did mine already i ran for 4hrs and 2qts oil was gone lotta oil and smoke came out too
was going for the 440 kit but i could'nt get the parts in time before i went to badlands so i just put in a
top rebuild with just new rings. still stock bore though just started racing and now i want the 440kit some bikes are fast in the b class for mx track and mine is slow.... i still want to all out on mine too looking for 440kit and found a bunch less than 200$ and will to spend about 1k $ on engine but maybe not since the new trx450 is coming out in nov.


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2000 400ex
slightly mod

 

i would not go bigger than the 416. the bigger you go, the hotter it gets. also, the less cylinder wall you have to work with when/if you need to rebuild it again. by the way, how do you like your stage 1 with the stock bore? how much power did it give you?

 

sorry it took so long to answer but when i put my stage 1 hotcam into my 400 it reved out alot faster which i like if u were to put one in i would sugesst a new rev limeter

 

sweet, i actually just ordered a 10.8 ross piston and a stage 2. i am only making it a 406(one mm bigger on the piston). however, my friend just ordered a stage 1. i wanted more top end so i went with stage 2.