motopsycho87

Member
Dec 26, 2010
152
2
... I know it sounds crazy, but has anyone thought the sound might be coming from the Helmholtz resonator unit? The one with the drain hole going to thin air? The valves hold this channel open until the engine is revving high enough to move the KIPS, the point when the sound goes away...

Just a thought...
 

motopsycho87

Member
Dec 26, 2010
152
2
No, it has a pipe union on it for spooge to drain from, the left side of the engine has a resonator unit.

I'm guessing its only on the 89-94 200 models, perhaps they blanked it off on the newer models to try and relieve some of the noise? Anyway, the resonator unit is made of cheese anyway, so very easy for sound to escape that way.

Looking again, might even be the SR model only, anyway, its a genius idea as all the spooge (not a lot) escapes out of that pipe, I'll take pics when I'm back from work later.
 

BSWIFT

Sponsoring Member
N. Texas SP
LIFETIME SPONSOR
Nov 25, 1999
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Interesting read. I had an '89 200 and the KIPS rattle was of no concern. I used Type F ATF and that quieted the clutch noise. I think typing this has used for thought than I ever expected on this subject. LOL:)
 

mudpack

Member
Nov 13, 2008
637
0
Actually, plastic will attenuate noise far better than cast aluminum will.
That's one (and only one) reason most cars/trucks now use plastic for intake manifolds, valve covers, and other engine covers... instead of metal.
 

dirt bike dave

Sponsoring Member
May 3, 2000
5,349
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Here is an excellent KDX specific article from Canadian Dave:

http://www.dirtrider.net/justkdx/kips.html

IMO, if you want to see if the noise is coming from the resonator, temporarily shroud it in something that will blanket the noise, like a peice of fiberglass insulation. If that quiets the noise to your satisfaction, then you can fabricate a permanent fix.
 

sr5bidder

Member
Oct 27, 2008
1,463
0
are you missing something on your head pipe? I see grooves for O-rings, does not seem to have the bolt on flange

my cover is aluminum and does not have the "spooge drain"
 

mudpack

Member
Nov 13, 2008
637
0
He appears to have the exhaust spigot in place, you can see the two gold-colored mounting bolts. The spigot seems to be chrome-plated!

The cover on my '06 is plastic/no drain.
 

motopsycho87

Member
Dec 26, 2010
152
2
Mine is the SR model, it has a bolt on spigot. I thought E models didn't have bolt on at all? The exhaust just sleeves in? Anyway, I made up 2 bolts with eyes for the springs and plonked an O-ring infront of the exhaust to fit!
 
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