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!
Posted: 05:06 pm Jun 01 2009
by Indawoods
I don't hear anything strange....
Posted: 06:05 pm Jun 01 2009
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...
Posted: 07:23 pm Jun 01 2009
by Julien D
Sounds just like a KDX dude. Ride it!
Posted: 08:34 pm Jun 01 2009
by Varmint
kips rattle and hum! Sounds normal to me too.
Posted: 09:22 am Jun 02 2009
by porterdog
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'.
Posted: 10:06 am Jun 02 2009
by Varmint
porterdog wrote:
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
Posted: 01:25 am Jun 03 2009
by shanana
100% rattle and humm kdx.
Posted: 02:03 pm Jun 03 2009
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!!
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.
Posted: 05:29 am Jun 04 2009
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 ?
Posted: 10:48 am Jun 04 2009
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).
Posted: 05:21 pm Jun 04 2009
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.
Posted: 06:03 pm Jun 06 2009
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
Posted: 06:19 pm Jun 06 2009
by canyncarvr
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,'
