tranny noises at low idle

I have a 08 yz450, luv the bike. New to thumpertalk so bare with me. Makes a knocking noise when lugging around in 1st or 2nd...but soon as u open it up the noise goes away. Dumped the oil out twice and checked the filter, never found anything but the normal stuff. Just wondering if anybody else has the same noise or if the yz450s just have noisy transmissions when being lugged. Any info would be appreciated.

It's the chain slapping the swing arm, and it's normal.

Check and see if the sound seems to come from the left side of the engine. It is possible that you are hearing the chain slapping around a bit while lugging it.

Man, you beat me to it Gray :eek:

ya its definately chain slap, happens on every bike.

O.K. ...yeah I was wondering that, but it never did that on my yz 250 two stroke...first thumper and lovin it..still lots to learn thou. Thanks gray...u seem to be the goto guy on here for the yz450

O.K. ...yeah I was wondering that, but it never did that on my yz 250 two stroke...
There's twice as much time between power strokes on a thumper, and each one is bigger.

Ya definately the chain slapping around. I put a new Renthal on it and it made it slightly better, but i still hear it pretty good.

There is also a growling rattle noise you can hear at idle in neutral with the clutch engaged that will disappear when you pull the clutch lever in. This too, is normal. It is the gears in the trans rattling against each other in response to the widely separated power impulses at idle.

If your head pipe begins to glow red, then you have problems! Ha Ha!

J/K.

It's all good....tightend my chain up a hair and it seemed to help because I didn't even notice it last night riding or maybe i'm just use to it now.

Review the manual carefully, and do not run the chain tighter than 2" as shown in the book. Broken hubs or worse can result.

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