01 YZ 426 Top End Rebuild

I'm the second owner of my 2001 YZ426 and to my knowledge, the bike has never had any top end work performed on it. Valve clearances are in spec, but I think its time to start pulling the top end apart for a general inspection/replacement. Also, the last 3 oil changes have shown some metal wear in the filter. I just had the clutch opened up a while ago and there was no indication of wear any any of the gears/basket etc so I don't think the metal coming from the oil filter is transmission related.

My questions are 1) Recommended replacement brands for the big hit items like: Piston, valve springs, gaskets, cam chain etc,

2) While the engine is apart anything else worth looking into aside from a basic top end rebuild?

3) Does anybody have experience with Hot Cams in their 426 and if so, is it worth the extra money to upgrade?

I'm sure there are postings like this from the past so if you guys come across one feel free to paste the link so I can check it out.

Any input is appreciated.


There are some really great threads here that cover all this. I'd et the hot cams or at least a auto decompression exh cam, will make life easier. Piston choices are numerous depending on stock or high compression. I'd do a full rebuild if u think it hasn't been touched. Check the crank condition side to side clearance, inspect the valves, replace with oem. Do some searching and all is there

It probably isn't a bad idea to take a look at the crank. Better safe than sorry. It will make a good summer project. I'll keep searching around.

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