How much noise is excessive on a 450?

[KVO-TN1-2beat]

My brother just got a YZ450 and compared to my DRZ400 the top end engine noise is rediculous. My DRZ400 had a slight tick in it that I was concerned about, but after riding several hours in the woods with my Bro. it's not an issue.

How much noise is to much coming from the top end? I know that the DRZ400 has had some issues with the ACCT, what about the YZ450? Are there cam issues with the bike I need to keep an eye on? I've never been around a 450, so I don't really know what to expect. Should I check the ACCT and chain? Or should I take it to the shop?

[MotoGoalie]

I know my bike makes a helluva lot of noise. If you put your ear down to engine level its really scary. It runs fine though.

Is it new or used?

[ACE_269]

I recently just bought an 05 YZ450 and just converted from the 2 stroke. I was/ a, kinda concerned about all of the valvetrain/ engine noise too. On a V8 car engine, you would think the timing cahin was slapping if it ws making that kinda noise.

So, I was wondering the same thing.

[BergArabia]

Mine makes a lot of noise and has since new..

[KVO-TN1-2beat]

It's a used '03 that was a dirt bike converted to SM and back to dirt. The fellow said he just had the top end rebuilt about 6 months ago and only had 1 race on the new rings and such. Compare to my DRZ400 this thing sounds like the Texas chainsaw massacre. If you all have a lot of noise too, I'm wondering if it's just the reason why they call 'em thumpers? If anyone has any input drop it in, I'd hate to blow money we don't have getting the thing looked at if it's a normal occurrence.

[Norman]

You might check the cam chain tensioner, if it is sprung all the way out not putting tension on the chain, its time for a timing chain. Ive had 2)YZ426's 3)CRF450's and even one of the Orange ones, they are all noisey, its hard to say what is excessive without actually hearing it.

[CycleWriter]

You're all forgetting one thing. The DR is a completely different engine design from a YZ or WR. The DR is a traditional overhead cam engine with actuator arms over the valves. The YZ/WR is a race-bred, 5-valve, shim-over-bucket DOHC design that is much more complex and noisier when operating. You could no more compare their sounds as you could their performance. In any case, it's always a good idea to have a used bike checked out before buying. Cheap insurance considering what an engine failure on a YZ or WR can cost to fix.

[Wayward Son]

a drz 400 is not a dr.its dual over head cam shim under bucket.they are on par in performance with yz/wr400.which is the bike it was designed to compete with in 2000 when it came out.

[falshh]

Yamaha 450's seem to make the most valve train noise for sure(although they are still reliable)

[CycleWriter]

a drz 400 is not a dr.

You are correct. My bad, but the Suzuki DRZ is a 4-valve design compared with the Yamaha YZ/WR 5-valve setup. More valves make for more noise.

[Drunken Monkey]

You are correct. My bad, but the Suzuki DRZ is a 4-valve design compared with the Yamaha YZ/WR 5-valve setup. More valves make for more noise.

not necessarily, the intake valves don't move as much.......

[KVO-TN1-2beat]

So bottom line is I should get it checked out, right?

[CycleWriter]

not necessarily, the intake valves don't move as much.......

What has that got to do with anything? You still have five cam lobes vs four. Five contact points vs four. Five valve movements vs four. Five shim adjustments vs four. And the chance for five areas to be out of spec and therefore noisier vs four. Valve travel is not the major factor in the noise, it's the interaction between the valvetrain contact surfaces along with cam profiles (ramp speeds opening and closing) and tolerances created by wear. Another factor is the casting of the head can increase mechanical noise. Open cavities can cause echoes that amplify engine noises making them sound more ominous than they really are. The Yamaha's open head design and tall, hollow valve cover contribute greatly in this area.

[CycleWriter]

So bottom line is I should get it checked out, right?

Considering this is a used motorcycle and the amount of damage and expense a stuck/broken valve could do, I would have it checked. Not necessarily a teardown, but at least checked against a similar bike. At a minimum I would check the valve clearances to see if they are in spec. Also, a worn cam chain can produce more noise. On a Yamaha, cam chain wear is critical since the drive gear on the crankshaft is not replaceable. Once it's worn you'll need a new crank.

[new2blu]

Mine is noisy too--sounds like a sewing machine;but that is the way it has been since it was new.

[Klx4me]

If you think the YZ is noisy then you should listen to a KTM. I had a SX450 which was a good bike, but it was considerably louder than the 05 YZ I currently have.

[rlp1]

Our YZ426 sounds like what you're describing too. It kind of goes chug chug clink clink, if you know what I mean. It had engine work done too, and it's in good shape. It sounds vaguely like a sewing machine, that's just how it is, DOHC, 5 valves.