400ex whining noise

[best400exever]

I have a 2003 400ex that is all stock motor wise. When I first crank it up It makes a whinning noise and when you ride it you can sometimes hear it. It runs great. My dad thinks it could be a oil pump. Is it normal? Any help would be appreciated.

[SteveWR450F]

My girlfriend's quad also makes similar noise. While it was under warranty, honda replaced flywheel and noise improved.

Still makes some noise though.

I would be interested in hearing other folks comments.

[bdtoady22]

i have a 99 and it also does this mines definatly on the clutch side. ive replaced cam chain and tensioner and checked every thing out and could see no problems. mine does it after start up and quits half way warmed up. it doesnt do i all the time though. the demon will rear its ugly head some time!!!lol

[Flodies400ex]

mine does the same thing and I have the 2004 400ex and I just think maybe the clutch is going out I think but not for sure tho

[Exrider434]

mine does that too. Glad im not the only one haha
:blah:

[NJ450rider]

Mine makes that low pitched whine noise as well. Its louder when you first start it and you can barely hear it once its warmed up. I honestly dont think its something going wrong. Mine has done it since i bought it. The first owner hardly rode it and it had less than 20hours on it. I have a late year 2001.

Maybe its sound from the carb resonating out into the intake tube under the gas tank???

[416exfreak]

Supercharger:chinese: :p

No, its just a noise that they make. My 02 has made it from day one. 400ex's just make some noise, that whining sound and the valves are always a little noisy.

You get used to it after a while. ;)

[400ex28]

I don't hear anything on mine, but then again I guess i'm used to it.

[best400exever]

Thanks for all the replys! I just wanted to make sure it was normal and that there was nothing wrong with mine.

[Flodies400ex]

yea I dont use my 400ex often so cause I ride my trx450ER

[dirtdigger71]

my 2000 400ex has done it since the day it rolled off the showroom floor.

[QuadManiac]

One of mine has always made the whining noise, the other doesn't... whiner is a better performer... go figure.