Rebuild!!!!!

[crazya**400exer]

Well the other day my 400 started making a really bad noise. I took it to th guy who always works on all my bikes he said that i need a new piston and camchain and a few other things. What do you guys think i should do to my motor sense im getin a rebuild finally??? oh and its geting bored so what should i bore it to 416 or a 426?

[BigGun311]

My friend has a 416 and it's pretty sick

[CJM]

407 11:1 piston, hotcam stage 2, 02 crf 450r cam chain. Replace cam guides and cam tensioner of needed. Should give you plenty of power.

Compressions power, no bore size. 16 or 26cc isnt going to make a real differnce. Bore the smallest you can,t his way when you need to redo it you can go up a size.

[Pittsburgh400ex]

How long did you ride it making the "really bad noise"? I'd ask to see the piston, i'd bet there is nothing wrong with it. Cam chain sounds really loud, like banging on a coffee can. I'd bet that was your only problem. I'd stay stock bore if you can and just up the comp. You said in your sig you do all the work on your own. Can you operate a mill and bore a cylinder at 14?

[crazya**400exer]

Well when i said that i ment ever thing except that kinda stuff haha, but i do everthing else includin pay for everthing unlike a lot of 14 year olds haha. But when it comes to some motor work i let somebody with some experience take over...But anyway back to the topic i think that after this rebuild im goin ta sale the ol 400 and get a yfz a buddy of mine is goin to cut me a good deal on one so if anyone is in my area and wants to buy it for $2800 its for sale!!!!!:D