Whistling/whining noise on acceleration

[Riding3]

I'm positive that the sound is not as a result of air through the shrouds. As described the sound is like a turbo spooling. However, the sound is not as loud as a turbo.

Plus, the sound usually would be heard at low lugging while powering on. There is minimal airflow when it happens.

[gottaroost]

I have that sound I've noticed when lugging too on my '06 YZ450..sort of a chirping sound. I remember hearing that on my '02 426 several years ago when it was new.

I was told then it was normal 4 ST stuff and it is the exact same sound now as it was back then so I have added it to my ignore list along with all that clutch clatter rattle. Hopefully yours is the same thing.

[tek_01]

I was just looking through some youtube videos and i found this one

Look specifically at 0:39 seconds onwards when he revs it. I know its not that clear but that is a very similar sound to what mine sounds like. (But saying that, things sound different through speakers than in real life)

So does his bike sound normal?

[rufusz]

That's intake noise....sound of air being sucked in the carb/engine. Don't worry if this is the only noise you're getting )

[Jim813]

I was just looking through some youtube videos and i found this one

Look specifically at 0:39 seconds onwards when he revs it. I know its not that clear but that is a very similar sound to what mine sounds like. (But saying that, things sound different through speakers than in real life)

So does his bike sound normal?

Judging from that video, my bike sounds almost the exact same ( expect I have a quieter exhaust with magnifies the "whistling" sound).

[tek_01]

Thanks, im at ease now

And now i have put a full jardine exhaust system on there it did muffle that sound even more

Riding tomorrow cant wait!

[dbyamaha]

i have a 08 yz450f and it does the same thing. All of freinds bikes do the same too. Its normal..

[Boise93]

I agree with dbyamaha, as my 08 whistles and has done so since new with 0.0 hours. At 75.0 sounds just like it did when new, I miss the sound when I ride my brother's RM450. Reminds me of riding a bottle rocket, the whistling kind.