Cylinder Head Help

[Intrepid]

Hi guys, I need to replace the cylinder head on my 2002 CRF 450R. The valves have pounded out the head (original I believe), and I'm not able to shim it any further.

I'm looking at buying an OEM head from here: http://www.bigborethumpers.com/newheads.html (Unless you guys have a better suggestion for vendor/price, I'm in Canada btw).

My question is, what else will i need to do this job? I'm trying to price out the project right now. I'll need a head gasket, right? Any special tools or other parts that I need to order? Any other advice?

Cheers!

-Cam

[Shawn_Mc]

buy a manual cam chain tensioner and a new cam chain too. If the piston hasnt been done, do it now. It'd be silly to break the thing down again...And, get a running time meter if you dont have one now.

The Big Bore thumpers 06 head deal is kinda hard to beat.

[Intrepid]

Ok, I can do a manual cam chain tensioner and cam chain also. Can you educate me as to why I want to that? Or point me to a thread?

Any recommedations on vendors for the cam stuff and the piston? Should I stick with Big Bore Thumpers for that stuff also?

And, there's great potential for this next question to be a stupid one, but do I need to measure my cylinder before I order another piston? Do I have to get my cynlinder bored and hones with every piston replacement?

I guess the reason I'm asking all these questions is I might sell the bike, and upgrade to an '08. I want to make sure I can sell the bike with a clean bill of health, is it necessary to do the cam tensioner/chain and piston if they don't need replacement right now?

I'm on the fence though about selling the bike, if I dump several hundered dollars into the bike it will be rock solid, and i'll know what I have. Buying an '08? While nice; I might be buying someone else's neglect, right? Anyone have thoughts on this?

[Shawn_Mc]

Well, the cam chains get tired. The OEM cam chain tensioners fail with alarming regularity and the 02-03 part was even worse than the newer style that STILL fail. Its not just bling. The oem tensioner being automatic basically has a clock spring that set the tension and then a jamming mech that fails. The problem is it can allow the timing to jump, and then the tensioner resets itself and cant figure out why the hell it quit, when nothing is obviously wrong.

The piston, if your on the fence can just be a OEM replacement. Get the 04 piston. (check ebay, sometimes i see deals that are just stupid, got my Wiseco for 55 bucks with gakets or something) The bore is nickasil, which means its only slightlly harder than the gates of hell. A quick pass with a hone will cut the glaze, impact the size of the bore exactly zero. But you need to cut that glaze so the new rings will seat properly.

The reason for a piston is, the piston is so short, its got hardly any skirt to it at all and when they get worn, they can literally turn sideways in the bore. ya, ugly.

if youve got mic's feel free to measure, but Ive yet to see a piston that was out of spec coming out of the box when compared to the bore. if all yovue got is a caliper, dont bother. It cant measure close enough to make any kind of informed decsion.

[APE Jay]

Ok, I can do a manual cam chain tensioner and cam chain also. Can you educate me as to why I want to that? Or point me to a thread?

Any recommedations on vendors for the cam stuff and the piston? Should I stick with Big Bore Thumpers for that stuff also?

And, there's great potential for this next question to be a stupid one, but do I need to measure my cylinder before I order another piston? Do I have to get my cynlinder bored and hones with every piston replacement?

I guess the reason I'm asking all these questions is I might sell the bike, and upgrade to an '08. I want to make sure I can sell the bike with a clean bill of health, is it necessary to do the cam tensioner/chain and piston if they don't need replacement right now?

I'm on the fence though about selling the bike, if I dump several hundered dollars into the bike it will be rock solid, and i'll know what I have. Buying an '08? While nice; I might be buying someone else's neglect, right? Anyone have thoughts on this?

We can handle it aqll. If you want to send your cylinder for us to measure, we can send it back with a new correctly fitted piston

[bikenband]

Just finished a rebuild on my '02 using the Big Bore Thumpers head. It was a good deal, made things easy, and the motor feels awesome. As Shawn said, do hone the cylinder. My local shop did it for $10, good for peace of mind.