HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
bluerider450

motor noise?

7 posts in this topic

i bought a 2004 yamaha yz450f a few months ago and i was just woundering do your guys motors make alot of noise around the valve piston area?

Share this post


Link to post
Share on other sites

Remeber, there's a lot stuff moving parts moving around in there that you're not used to. Another thing that makes it noisier is that it fires half as often as a smudge pot. This means that at low speeds, idling in neutral, it fires, slaps all the slack out of the valve train, clutch, and transmission, and then comes crashing up against its own compression stroke. When it does that, it looses 50-200 rpm almost instantly. All those moving parts are like people standing up in a bus that just jammed on its brakes. Then, right after that, it fires again.

Another thing that happens is that at idle speeds, the cam assemblies tend to get driven by the valve springs as they rotate past the full open postion. This puts a whipping action into the cam chain, but it disappears as the engine speeds up a little.

Check this out. With your bike idling in neutral, pull the clutch in and see how much quieter it gets. You'll get used to it. :cry:

Share this post


Link to post
Share on other sites

yeah i noticed that when i pull in the clutch i was just making sure it wasnt anything bad and seeing htis is a post for the bike i figured alot of you guys would have answers thanks

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0