KX rattling on deceleration

[MXTex]

When I get out of the throttle on my 98 KX250, it makes a rattling, slushbox kind of sound. Not too long ago, I replaced the pipe springs, sealing o-rings and that washer that fits between the pipe and the cylinder. This solved the problem for an incredibly short period of time. Now it's making the sound again. I've isolated the springs and it still makes the sound. So it must be that washer that fits between the cylinder and pipe.

Any suggestions for replacement or modification of that washer that may last a little longer than the stock unit? Maybe a little high temperature silicone on both sides of the washer? Maybe a washer from another brand? I never had this issue on my CR. Would a Honda piece work?

Thanks in advance.

 

[Senior KX Rider]

Silicone works well. :)

 

[bigred455]

The honda washer is too small for the kx cylinder ,the kx copper washer loses it's thickness really quick.You can machine one out of steel like the cr,so it will fit your cylinder.

 

[DMATT125]

bigred has a great idea. i have found silicone to be messy and a pain in the butt on previous bikes. if you have one machined use stainless steel. you wont have a problem with rust,and it holds up well to heat. your local machine shop con whip one up pretty cheap.

 

[mike rasponi]

WAIT, before you tear apart the exahust, check the rear shock, there are two self locking nuts that spin around the shock....is it that? i looked for the longest time and i couldnt figure out what on my KX250 was rattling...until i checked the back of the bike ;) try taking a hammer and screw driver and tapping gently while using the screw driver as a dowwel. just a thought.

 

[buffmaster]

Instead of silicone, try a high-temp sealant. I used it on mine(can't remember the brand, but it comes out orange), and has worked great so far, but it's a b*&$h to get off of anything, so be careful when applying.

 

[smb_racing]

permatex hi-temp sealant is what I use on my KDX's pipe. I noticed an odd rattling sound on my bike and couldn't think of what it was until I noticed my clutch lever is worn and won't tighten clear up. Make sure everything else is tight unless you're absolutely certain it's the pipe.

 

[KXsteve]

My 97 KX 250 does this, also. I have tried the silicone, but not with any luck.
I have a Pro- circuit pipe on mine (was there when I bought it!) Does any one think that its because of the pipe, or do the standard ones do it too?

Steve