400ex engine noise at startup

[NJ300ex]

At startup and when its cold does your 400ex make a whirling type noise. It kind of sounds like when you have your windows open a little bit and the air is coming in. It is coming out of the engine in the front part.

[Ex'rMike]

Yeah all of the ones I have heard do that. I believe it is the oil pump.
-Michael

I'm with ExerMike on this one, I'm sure it's the oil pump making that kind of noise. I don't think it's a bad thing, I just think it's letting you know it's working:D

[NJ300ex]

Does anyone elses 400ex make this noise?

[400exdad]

Mine does. I wish it sounded that smooth all the time.

[fourplay]

My quad does the same thing when its cold. Its done it since I got it new.But still runs strong!!

[nigsrig]

mine does it too,,had it a year and its still running strong