What problems? (Part 2)

Got a new 2001 YZ426 last week, put a couple hours on it, love it, and now I've just completed the breakin maintenance.

Just like everyone said, the oil was DIRTY, with a silver color, lots of metal in the oil filter too. No metal in the frame strainer though, because it was torn (glad I bought the metric impact sockets just to check it). Shock oil had a little metal too.

There were gobs of grease on the swingarm and stearing head bearings, so maybe Yamaha has finally started doing it right. But wait, no oil on the air filter though!!!

The one thing I wonder about was the valve clearance...it was absolutely right at it's minimum specs, .004 on intakes, .008 on exhausts. I expected the valve clearance to be at the large side of specs and then get smaller over time (due to valves sinking into heads). Anyone have any experience with this?


2001 YZ426

2000 Harley Police Special(I actually get paid to ride this one)

The frame strainer was torn? The dealer should give you a new one, since it must have come that way from the factory. If you have any trouble getting one, I have an extra one around here somewhere.

You already tore down the shock? If so, then you should really disassemble the forks also. They will be dirtier than the shock.

You rode it without servicing the air filter? Bad move!! I would chuck it and get a couple of Twin Airs.

The valve clearance hardly changes over time on these bikes. Check it again in 3-6 months to see if there is any change.

If I remember correctly the manual says to check the valve clearances after break in so I would not be surprised if they are close to needing adjustment. I haven't checked mine yet but after reading your post maybe I will (just did my 2nd oil change). I also had lots of metal bits in the oil filter after the first change, but none in the strainer so I wouldn't sweat too much about the torn strainer at this point. Be sure to get a new one before you ride again though! There was less metal in the filter after my 2nd oil change but still a little bit. The oil looked horrid after both changes (grey with tiny metallic flakes), from what I hear this is normal. My air filter was nicely oiled though, I wonder if the dealer did this for me?

The manual also says to change the fork oil after break in which I haven't done yet (on my to-do list). If you do this then please let us know what you find. Also how did you change the shock oil, are the required tools expensive?

I also had globs of grease oozing from the swingarm bearings and steering head, maybe they fixed this for 01'.

I've been shocked and pleased that the valves shims hold up so well on these bikes. I've put alot of hard miles on my bike and it continues to remain within tolerances. Other 4-strokes I've owned were slapping after 10 hours of riding. Anyone else had similar success?

Sorry, meant to say fork oil, not shock oil. I'll run the same shock oil until winter, then have a local shop change it.


I saw you drive a Harley at work. Must be cool. I drive a 2000 BMW K1200RS Police Edition at work, and it`s great. I collect pictures of different police bikes from around the world. Would it be possible for you to send me a couple of pics of you and your bike :-)


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