Bulletproofing my 00' 426 motor?

Got a 2000 engine that is getting a complete teardown and rebuild. Here's the issues I know and what I've already done:

-clutch. Already updated to 2001 spec

-straight key on crank. Ordered a new one and will replace]

-cam chain and tensioner. Got new ones for replacement

-previous owner replaced 2nd and 3rd gear back in 01' or 02', not sure if these are problamatic parts or what!?!?

What am I missing? Does the motor have any glaring weak points that I'm missing? Crank or rod bearings, shift fork.... anything?

I'd rather do some preventative maintenance now rather than split the cases again in a year.

Thanks for all the help people and putting up with my PIA postings :naughty:

I believe either the '01 or '02 got a bigger rod bearing. The earlier ones have been known to fail, rarely. You might look into a later model crank assembly. If you do, watch out for compatibility with the primary drive gear. One of the 426 guys will know.

I think the rod bearing was actually changed when they changed over to the 426 in 00. Other than the stuff you listed Brandon, I think you should be set.

install the 450 exhaust cam and then a hinson clutch basket. Be sure to clean the filter screen at the bottom of the frame downtube and check all metal sleeve guides that the oil lines line up to on the motor (ie make sure they dont get crushed)

Got the cam already and I'm considering the Hinson, but I cant afford to replace all the compenents with Hinson pieces. Is the basket itself the most significant of the set?

I know they also make the pressure plate and hub, but I cant swing that much $$.

I'll be sure to check all oil lines, tubes and the pick-up. I've also got all new gaskets, seals, crush washers, etc....

Thanks everyone.

just get the basket.

The stock basket wears so bad, that is fills the oil with shavings. I have used a hinson on both YZFs that I own and never had any more shavings after swapping to the aftermarket hinson basket. Personally I dont like my oil to be full of shavings going through the top end of the motor.

As long as you're taking the motor down that far you might as well replace the crank bearings. I think they're about $32/ea or so.

Ordered a PE basket yesterday, hope its as nice quality as others have said. As for the crank.... I'll definately replace the bearings. If the cam chain gear is worn then I'll be replacing with the 01' crank and rid myself of the straight key.


Didn't the 2k model have failure prone 2-piece valves?

the clutch basket is definately a good thing to replace. mine wore really bad then blew up. i replaced it with a hinson and everything has been good.

If you have the 03 cam and have removed your decomp lever in the head, replace the $3 Yamaha plug with the TT decomp plug, it won't blow out.

2 piece valves? I have never had any problems with the valves in the 2000. They are steel instead of titanium in the 2001 and later I think.

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