okay, my 05 kfx400 has an oil burning problem. it needs to be rebuilt. should i bore it out? i was thinking of boring it 40 over which i have a machine shop to do for me. i also hear all this talk about hot cams but idk where to get them and how much help (power) they will really be. also, is there a stroker kit because i figure if im gonna work it i may as well do it big....... "go big or go home" right? you tell me, i am new to this. thanks

 

ya it depenns what you jug looks like ,if it has a good deal of ware then ya if not a higher compreshion piston with new rings may turn that Z of yours on more than what you may think and for a lot less money than a BBK ,and if you dont have all the suporting mods your not going to get as much out of the BBK as you might think.
porting helps and after all you will have the head off , make sure you check you intake valves, them things have a history of wearing out faster than they should and you may as well have new seals put on the valves.
and yes get the cams , hot cams are working rather well for me.
BTW my Z is a stock bore with a 13.5:1 compreshion piston and i am getting over 40 hp
have you changed your timing chain yet, now would be a good time .

 

on the kfx/z400 motor if you bore the cylinder it has to be nikasealed and most machine shops dont do it. when I did mine we had to send the jug back east to have it resealed. IMO if you want it bigger then buy a 440 or a 450 kit that comes with a new jug. and cams really do make a difference. as for stroker kits here's a web site for you kits