rebuild parts

[racer36]

I know theres got to be threads for this, but i cant find any. my question is, What is the part list for a top end rebuild? and should i get it bored or leave it alone? its stock and burning oil bad, so i think its time. any help appreciated, thanks

[hocman123]

well u really dont know untill u open it up and look inside might just need valves and rings and be good. but if u are taking it apart i would say u want a top end gasket kit. the honda stuff has never failed me. but i do belive the valve seals do not come in it so order those also. also look into a hot cam 1 or 2 depending on what u do to ur engine.

also is good time to change ur timeing chain and upgrade it to a crf 450 chain.

if u open it up and find u ned to bore it then i will have a much bigger list for u

[CJM]

Wont know if it needs to be bored till you get it measured by a machine shop.

I wouldnt even bother with a honda topend kit.

Go to cometic.com and buy one, its cheaper and its got better gaskets. It comes as an entire kit iirc. You can order the 86mm or whatever size you want-it doesnt matter.

[mlabarca240]

I would highly suggest you bore it a half to one mil over. This would take care of any scoring or if the hole isnt perfectly round. I also used a cometic gasket kit stock bore size and its been holding up fine, with a 1 mil over bore that is. If you overbore be sure to send your new piston and rings to the shop along with the tolerance sheet they send with it so they can spec it. I went ahead and threw in a HC stage one cam and a Wheelie +3 degree timing key. VERY strong motor.

[racer36]

alright sweet, thats all i was thinking too, but just didnt want to miss anything. I can still run pump gas with it bored just a little and a cam right?

[hocman123]

well octane will depend on what type of comprision u get on ur new pistin if u get 11-1 and a stage 2 cam u should have no problem with 92 or 93 pump gas

[racer36]

alright thanks

[mlabarca240]

I run 93 with an 11:1 weisco, Wheelie +3 timing key, and an HC stage 1 cam. It runs really well but pings after a super hard run and lugging down the motor.

[hocman123]

if u didn't have the key u would never have that problem but from what i hear about timeing keys it might be worth it

[CJM]

Yep, the key advances the timing so much with the higher comp piston you need to run 100 octane. Could run a mix tho of 93 + 100 or 110.

[mlabarca240]

Yea, I knew it would be a gamble. With 110 goin for almost 10 bucks a gallon and 100LL goin for 5 a gallon....I'll just take it easy and run it a little fat for now.

[CJM]

Indeed, thats why I didnt put the key in myself. Cant find 100 here to easy let alone 110..

Only thing I wonder is if I shoulda done a stage 1 hotcam for insane low torque.

[mlabarca240]

The stock cam has the most low end torque believe it or not. IMO that is. Id bump the compression and go with a stroker crank for torque. The stage one adds gobs of mid range.

[CJM]

I found with a 11:1 piston and stage II cam I gained all around but mostly mid. Right gearing which I finally think I figured out should work well too.

[hocman123]

Originally posted by mlabarca240
The stock cam has the most low end torque believe it or not. IMO that is. Id bump the compression and go with a stroker crank for torque. The stage one adds gobs of mid range.

i don't know about that me and my friend have stock bikes but mine has a lot more use on it and has a stage 1 hot cam and thats it. when we race i allways fly out infront of him in first and second gear. but once we hit 3rd and up we stay even. He will not get me, but i will not get a bigger lead. And its not a small lead i get like 2-3 bike lengths between me and him.

and he is a better rider then me

[CJM]

Originally posted by hocman123
i don't know about that me and my friend have stock bikes but mine has a lot more use on it and has a stage 1 hot cam and thats it. when we race i allways fly out infront of him in first and second gear. but once we hit 3rd and up we stay even. He will not get me, but i will not get a bigger lead. And its not a small lead i get like 2-3 bike lengths between me and him.

and he is a better rider then me

Agreed, Ive seen it myself. My quad will pull on them bad no matter what unless Im easy on it. But there are identical besides the hotcam. Also riding each of them a few times myself the hocmans with the hotcam has more power.