valve clearance readings/noise solved

I checked my valve clearance today on my 99wr400, and I came up with just right at 2/10 of 1mm tight on all of them. So, real close to .23 on the ex and .13 on the intake. This thing has never been touched so it was predictable that they would be a bit on the tight side, but they sure were not as far out as I expected. So I was wondering about a couple of things. One, how dangerous is that minimal clearance for the moment? About the only risk is a burnt valve am I right? How realistic is that risk under these circumstances? The other question is what sort of shims are usually found in these from the factory? Is there allmost allways at least one shim between say 2and4 thousands that I can count on just removing and calling it good? Reason I ask is that due to my location getting shims is going to be a task, so was just looking for some realworld feedback on where I stand.

As an aside, I had that sorta annoying noise coming from "somewhere down there". I took the clutch cover off and found a strange little flaw in the side case where the material had a raised spot, and the clutch basket was just so slightly rubbing up against this spot. A few minutes with a dies grinder and Viola, no more nose. -Amen-

Thanks as usual,

Mark Sheldon

Specs are 0.10 to 0.15 mm for intake, and 0.20 to 0.25 mm for exhaust. So, 0.13 on intake and 0.23 mm on exhaust isn't tight, it's right in middle of proper range. My 2 outer intake are still at 0.13mm after 7000 miles. You just want to make sure they stay in the range called for, and adjust before going past limit. Replacement shims only come in 0.05 mm increments, and some original uneven numbered shims can sometimes be switched around for finer adjustments...

Well, I guess I'm a bit confused. I got it on good faith from a user here that the specs were


You are correct..... .15mm ~ .20mm (.0059 ~.0079 in) for the intake and

.25mm ~ .30 mm (.0098 ~ .0118 in) on the exhaust. Taken right out of my '99 WR400 manual.

So, .23 and .13mm according to those specs are both a scosch tight no??? Again, this is a 99, and readings were cold.

Please advise folks,

Mark Sheldon :naughty:

did I have the wrong specs?????

Valve clearance cold


0.15~0.20 mm (0.0059~0.0079 in)


0.25~0.30 mm (0.0098~0.0118)

Right out of my manual 99 WR 400

I just did mine and was only able to use one of the old shims.

It's not very hard and only took about 2 hours.

If I had to do it again today it would only take me about an hour.

I have heard where some peaple take a little material off their shims with emery clouth. You might want to try that if finding shims is a problem.

My 2002 manual actually has the same specs for both the 426 and 400. I guess the '99 was different...

0.125 mm is half way between 0.10 and 0.15 mm, so 0.13 is 0.005 on the 'slack' side. At any rate, 0.13 mm intake clearance is good. If the actual shim # is a multiple of 0.05 mm, say 0.190 mm, you could either go to a replacement #195 shim (1.95 mm) and end up tight at 0.08 mm, or go with a replacement #185 shim (1.85 mm) for a loose 0.18 mm clearance. Some original shims are not multiples of 0.05 mm and can sometimes be switched around for minute adjustments.

I used emery cloth (and a micrometer) to thin a shim, but it wasn't easy as it's very hard metal.

well, if it aint broke dont fix it. Im gona leave it be for a spell, its running like a top, a top with a V8. Its funny, the people down here just stare at this thing with thier mouths open when I get on it, all they have down here are cheap Brazilian Hondas with drum brakes, they call them "Tornados" at 225 CC, god they are crap, I feel like a Roman. Good thing I didn't get the Husaberg, heehee.

thanks all

mark sheldon

all they have down here are cheap Brazilian Hondas with drum brakes, they call them "Tornados" at 225 CC, god they are crap

Here's a pic of one of these "bad boys" taken in LaPaz, Bolivia last fall...

If they are out of spec you should re shim or you stand the chance of them tightening up more and burning a valve. Good thing you didn't buy the CRF 250.

Well, I'm going to try this one more time. At my valve readings of .13 and .23 (see above posts), these are not "slack", they're tight like I said the first time right?? Ok.... I sand them then yeah? Can I get whitness? I'm going in... somebody STOP me!

Mark Sheldon :naughty:

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