Strange noise?

Got questions? We got answers....
Post Reply
User avatar
JoKDX220r
Gold Member
Gold Member
Posts: 201
Joined: 04:04 pm Oct 03 2008
Country:

Strange noise?

Post by JoKDX220r »

Hi all,

Here's a link to a video I made of a strange sound my KDX started to make when I do my first "real test" of the year ( ride from a full to an empty tank )


The sound start at 00:05...

It first started when I was in 2nd close to shift in 3rd and still a while after I put it to neutral.. but now I can ear it even in neutral without riding it...

Can this only be a normal sound from carbon on kips or something's wrong ?

Thank You!
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

I don't hear anything strange.... :neutral:
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
User avatar
JoKDX220r
Gold Member
Gold Member
Posts: 201
Joined: 04:04 pm Oct 03 2008
Country:

Post by JoKDX220r »

it start at 00:05 kind of "background sound"...

But engine start at first or second kick even cold... the only thing other than the sound, I noticed a real change in "power" when the engine warm up...
More torque cold than hot...
User avatar
Julien D
KDXRider.net
KDXRider.net
Posts: 5858
Joined: 07:53 pm Nov 07 2008
Country: USA
Contact:

Post by Julien D »

Sounds just like a KDX dude. Ride it!
Image
User avatar
Varmint
KDXRider.net
KDXRider.net
Posts: 823
Joined: 01:33 pm Oct 27 2008
Country:
Location: Bristol, Connecticut
Contact:

Post by Varmint »

kips rattle and hum! Sounds normal to me too.
In my garage
2003 KDX200
2003 KX85
2005 CRF230F
2009 300 XC-W(e)
My KDX
porterdog
Member
Posts: 69
Joined: 10:33 pm Mar 22 2009
Country:
Location: Detroit (Rock City!)

Post by porterdog »

>|<>QBB<
JoKDX220r wrote:... I noticed a real change in "power" when the engine warm up...
More torque cold than hot...
103% normal; I usually start mine after I have ~75% of my gear on and let it warm for ~5 min before riding. Even then, it takes 3 or 4 minutes of motion before it's operating 'normally'.
User avatar
Varmint
KDXRider.net
KDXRider.net
Posts: 823
Joined: 01:33 pm Oct 27 2008
Country:
Location: Bristol, Connecticut
Contact:

Post by Varmint »

>|<>QBB<
porterdog wrote:>|<>QBB<
JoKDX220r wrote:... I noticed a real change in "power" when the engine warm up...
More torque cold than hot...
103% normal; I usually start mine after I have ~75% of my gear on and let it warm for ~5 min before riding. Even then, it takes 3 or 4 minutes of motion before it's operating 'normally'.
+1... same goes for me
In my garage
2003 KDX200
2003 KX85
2005 CRF230F
2009 300 XC-W(e)
My KDX
shanana
Member
Posts: 6
Joined: 06:16 am May 04 2009
Country:

Post by shanana »

100% rattle and humm kdx.
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

I hear a bit of a bog off-idle..something that probably is a lot more pronounced under load.

Other than that...I don't hear anything of import..

.
.
.
..'cuz of all that racket!!


:wink:

The hotter the pipe gets, the faster the pressure waves move in it, the greater the scavenge/ram effect that a 2T has. Depending on how it's tuned that increased wave speed may equate to a worse OR better running bike, either situation can be diagnosed using the wet-line jetting method (like...who does that, anyway?).

Point is, pipe heat makes a difference.
Last edited by canyncarvr on 10:53 am Jun 04 2009, edited 1 time in total.

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
JoKDX220r
Gold Member
Gold Member
Posts: 201
Joined: 04:04 pm Oct 03 2008
Country:

Post by JoKDX220r »

Thanks CC for this explanation, especialy thanks for hearing the bog it confirm that it's not "in my head"..
You're also right it's more pronounced under load, I was surprised I can film it without riding it...
Can that be a sign it will only get worse ?
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

What others were replying to was the rattle/racket from the engine. Which...is what I thought you were asking about myself.

The off-idle response part I figured to be completely by the way.

No. That isn't 'normal'. That is a state of tune that can almost always be resolved. Part of it is..I suspect you have the air box lid off? Complete removal of the lid lets you hear quite an intake 'honk' when you twist the throttle. It's harder than you might think to separate that noise from a perception of a real throttle response issue.

IF it's only the sound you are concerned about, don't worry about it. IF that sound translates to a throttle response issue (hesitation) when riding, that can be addressed. Given an engine in good condition (rings/piston-cylinder clearance etc) and associated hardware in good condition (reeds for example), throttle response is a matter of carb tuning (jetting/adjustment).

Re: 'Can that be a sign it will only get worse?'

The answer that probably best applies is, 'No.' Meaning it's not a matter of wear, bearing failure, or other hardware degeneration that's the issue.

Specifically, a poor throttle response that is related to less-than-great jetting will change with the seasons. A bike that's too rich when it's 40º is going to be considerably more too rich when it's 100º (talking about weather).

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
06KDXR
Member
Posts: 1
Joined: 12:04 pm Mar 20 2009
Country:
Location: Knoxville

Post by 06KDXR »

Your slow jet may be a little too fat. Get a smaller one and try that. Mine was the same way when it warmed up around here. Causes kind of a "pop" when you come off the throttle.
NewMexico505
Member
Posts: 78
Joined: 08:41 pm Feb 12 2009
Country:
Location: Albuquerque, New Mexico

Post by NewMexico505 »

Another thought, the video microphone may not be picking up the noise you are hearing...so we cannot hear it on the net here.

-Erik
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

>|<>QBB<
NewMexico505 wrote:Another thought, the video microphone may not be picking up the noise you are hearing...so we cannot hear it on the net here.

-Erik
But...he said:

'Thanks CC for this explanation, especialy thanks for hearing the bog it confirm that it's not "in my head"..
You're also right it's more pronounced under load,'

The bog sound IS the issue.

...my understanding anyway.

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
Post Reply