motor rebuild?

[shallow518]

right now my motor is beyond blown. she smokes worse than any 2 stroke, head gasket is blown to the point where it sprays oil everywhere, and i can tell she aint got half the power she used to. my question is how to go about it. its alreasy bored .40 over. so how big do i go? i dont want a huge bore cause i want something reliable and wont get to hot, but a lot of power. so besides going with a huge bore what else can i do? i need new valves so i was thinkin about titanium ones. i already have a stage 2 hotcam so thats covered. are HD valve springs worth it? my cam chain is probly ready to be replaced so should i put XR400 cam chain in it? im also thinking about porting and polishing the head but not sure if its worth it. ive also herd people who shave there head and all sorts of things. i know i can go real deep into this motor but when do i draw the line?

[LeGaCyGiAnT124]

It's really up to what you have done to the motor and what you use it for. I ride/race Xc type riding with a JE 416 kit with a hotcam stage 2. Mine was bored .40 over and I thought that meant a 440 but really it was only a 408cc. I think the 416 kit was worth it as well as many others. I wouldnt go beyond a 440 if it was me.

[NickG5755]

put a CRF cam chain in it..

[shallow518]

thanks for the help. is there a big diffrence between a 416 and a 426? im looking for the best thing for racing MX, and stadium cross.

[alex10]

Just go to a 416 and when it blows you can go to a 426. Get new oem valves and a valve job done. Don't forget valve seals and a CRF450 timing chain, from an 02. You can get one for like $42 from bikebandit.com.