Little help for you WR Lords.....

I wanna just ask you guys summut.

I went for a little ride on the WR426F supermoto yesterday for the first time, is it normal for the engine to sound as if there is a chain inside the engine slapping about a bit under throttle?

Felt as if summut needed screwing tight, its the first time I've had a day off to actually ride it a good way and get a feel for the bike, it could be just me as the other guy did take pretty good care of it from all accounts, but it sounded as it was a bag of nails in the engine.

(first time I've ever owned a single so dont laugh you bastards)

Could be summut simple like something needs some slight adjustments??

Sure had fun on it though, what a laugh, got a digi bike speedo, had a little gang of 17 years olds round it when I came out of the shop, gave it the "yea cool innit, its got this, its got that.....then couldnt get it ****ing started, forgot to pull out the hotstart choke thingy majig......then stalled it....shit I'm gonna HAVE to get to grips with this kickstart...had cramp in my arse for about an hour afterwards!! would be good.


You could actually be hearing the drive chain slapping, witch is a

easy fix, check under the chain guide for wear, if the guide is grooving

into the swing arm then you have found the problem.

As for starting install the YZF 450 Exhaust cam ( there are many post

on this ) and you will want to keep the bike a H#LL of a lot longer.

G Luck Jerry :cry:

Yes chain slap is a big problem with the WR under light steady throttle.

Recommend putting 1/2" thick layer of black RV silicone under the entire chain buffer slider on the swingarm. After the silicone drys 24 hours use longer bolts to hold the slider down to the swingarm. My silicone has been on the bike for over a year now and has not wore off yet. Protects the swingarm from wearing thru prematurely as well. :cry:

Got a pic of what you mean??

Is it the black rubber guide on the top of the swing arm for the chain to run along??

Because it has this already.... :cry:

Yes thats it now take it off and apply the silicone as indy instruckted

Ok someone has to post a pic of this....

How do you get the silicone to dry 1/2 inch thick??

Apply a good amount let it dry and trim the edges with a knife.

Mine is about 5mm thick.

Sorry to sound like a TOTAL chimp but whats this gonna do exactly?

Why not just tighten the chain?

My guide aint worn though yet anyway....sorry but cant get my head round why we are doing this??!!

I removed the bolts and the top hat washers on mine an gave the washers a tap with a socket(to bend em down a tad an take up the free play between washer and chain slider)refit an problem solved! :cry:

Sorry to sound like a TOTAL chimp but whats this gonna do exactly?

Why not just tighten the chain?

My guide aint worn though yet anyway....sorry but cant get my head round why we are doing this??!!

The chain guide on the WR sometimes slaps the swingarm when the chain slaps on it... this makes alot of noise. You put silicone under it or a used section of innertube or whatever to pad it so it damps the sound and the damage to the swingarm. Tightening the chain will not solve the problem without damaging the drive since the chains needs to be set to the factory spec.

Also, the WR (and all new thumper motors) sound like metal thrashers inside the motor. It is normal since they are so thin that you can hear everything in the engine. I have 1600+ miles on my WR450 engine and it sounds the same as day one and runs like a champ... hope this helped.

Cool thanks chaps.


YES, you probably have the chain too loose. MY 400 did the exact same thing. I replaced the slider only to have it worn out in about 200 mi. :cry: I went back to the manual and found out the proper way to adjust the chain (had been going by the "feel") and found that it was WAY too loose. You are supposed to measure from the back bolt on the swing arm slider up to the center pins of the chain when you are pulling the chian up. This measurement on the 400 is supposed to be aprox. 2 in. This may seem like a good bit but when you concider that the chain (relaxed) is already about 3/4 in away from the bolt, it is not much. I tightened my chain up to this spec. and have not heard the thing since July. Try measuring it like this and I will bet you are way too loose. :cry:

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