Just bought 06' 450F: Very Converned over Engine Noise

[bhsballer76]

I just bought a 2006 YZ450F. I have been wanting one for a while and thought I found a good deal. Last week I bought a 2006 KX 450F because I couldnt find a yamaha in good shape untill this weekend.

So I get the YZ home today and I notice how noisy it it. I mean, its really concerning me. I then crank up the KX and it seems to have 4 stroke engine noise to it.

I am going to pull the top ends off both bikes tommorow. IS THERE ANYTHING I CAN LOOK FOR TO REASSURE ME THE BIKE IS OK?

play in the crank? valve clearances? cam chain tension?

Also, would the thickness of the valve shims indicate how much life is left in the valves??

I got the bike from a second owner who said he put 65 hrs on it while the first owner put 10 hrs on it. The second owner said he pulled the cylinder at 40 hrs and noticed a slight scratch on the cylinder wall and so he replaced both the cylinder and piston at 40 hrs. He said valves have never had to been adjusted.

GUYS....PLEASE HELP..the yz looks like it was maintained much better than the kx, but the kx seems to be much quieiter and smoother in terms of engine noise...I cant afford to keep both bikes, but the one I keep I plan on having for at least 3 years.. I cant afford to keep the Yami if its a ticking time bomb..

Here are videos of both.. The first it the yz.. You can hear the knocking sound much louder than on the kx, which is the second video..

http://s146.photobucket.com/albums/r279/bhsballer76/?action=view&current=108_2312.mp4

http://s146.photobucket.com/albums/r279/bhsballer76/?action=view&current=108_2313.mp4

[kyle450rider]

I have a 2007 with 38hrs on it. My bike is noisy in the top end. It concerned me but from what I've read on TT some of the yamaha's are just like that.

[bhsballer76]

I have a 2007 with 38hrs on it. My bike is noisy in the top end. It concerned me but from what I've read on TT some of the yamaha's are just like that.

As noisy as mine??lol..

[Mr. Neutron]

bhsballer76,

I've read on here that bikes with an aftermarket skid plate tend to sound much noiser than they would without one. Try taking yours off, if it's an aftermarket, or a bigger offroad one, and listen if it's quieter..... There's actually quite a few threads here on that very subject. I guess when Yamaha went with the aluminum frame, the bigger/heavier duty aftermarket skid plates made the engine noise louder..... ? I'd sure look into this before I tear into the top end.....

I'm about to find out first hand the difference in noise sometime soon; I just got a ThumperTalk skid plate to put on my '06. I plan to put some sorta rubber insulator between the frame & the skid plate, in an effort to help keep it quiet.

Jimmie

[bhsballer76]

bhsballer76,

I've read on here that bikes with an aftermarket skid plate tend to sound much noiser than they would without one. Try taking yours off, if it's an aftermarket, or a bigger offroad one, and listen if it's quieter..... There's actually quite a few threads here on that very subject. I guess when Yamaha went with the aluminum frame, the bigger/heavier duty aftermarket skid plates made the engine noise louder..... ? I'd sure look into this before I tear into the top end.....

I'm about to find out first hand the difference in noise sometime soon; I just got a ThumperTalk skid plate to put on my '06. I plan to put some sorta rubber insulator between the frame & the skid plate, in an effort to help keep it quiet.

Jimmie

Thanks. I will def do that since it only takes a minute to do. Its not a huge skid plate, but it is a slightly larger than stock works connection skid plate.

[gscx]

They both sound the exact same to me. lol

[bhsballer76]

They both sound the exact same to me. lol

yea, its harder to tell in the videos. In person the yz is much more loud in the engine.

[grayracer513]

YZ450's are notoriously noisy. The first thing to do is to compare yours to another one. Most of them sound like the National School of Pipe Fitting.

[gscx]

whats causing it? Is the 2010 engine just as noisy?

[grayracer513]

A lot of the noise is generated by the backlash in the primary gears. They made a change in '08 to address this, but I don't know how successful that was.

[tech24]

whats causing it? Is the 2010 engine just as noisy?

My 2010 is considerable less noisey than my '04.

It sounds normal to me idle seems a little low too so I hear more engine than exhaust

[Mikeb12]

i have an 04 that i maintain meticulously that sounds about like that. I also think your idle is a bit low which amplifies the sounds but my first reaction to your video was that it sounds like a yz450 to me.

they do sound like they have rocks rolling around in the motor but i promise, there are no rocks (or marbles) in there. i checked. that being said, i understand your fear and only a look inside will tell the tale but do know, yz motors are noisy.

[Steel Panther]

my 09 sounds the same, it makes kind of a whirling noise at idle. Its been like that since the day I rolled it off the show room floor.

[Ga426owner]

Yzf sounds normal to me....

[sacfelix]

My 06YZ450 sounds the same way. I originally thought it was going to blow up after I put a skid plate on so I bought a can of rubber under coating and sprayed the inside of the skid plate.

[dvn]

my 09 sounds the same, it makes kind of a whirling noise at idle. Its been like that since the day I rolled it off the show room floor.

+1 The skid plate definitely amplifies it. Line your frame rails where the skid plate contacts them with strips from an old inner tube. It helps.

Edited November 22, 2010 by dvn

[davcon]

Just went out to record. Mine is noisy too. 119 hours. Timing chain changed at 90 hrs. No other top end work done except valve adjustment. Well maintained and treated.

[Troutman]

My 06 was very noisy in the top end as well, very normal. That bike was as reliable as an XR 80.

[bhsballer76]

Just went out to record. Mine is noisy too. 119 hours. Timing chain changed at 90 hrs. No other top end work done except valve adjustment. Well maintained and treated.

Hey, really appreciate the video. Really eases my mind . I pulled the tp end today and found a weisco piston and jug in mint condition. The guy i bought it from said he installed both at about 40 hrs.

[jrny426]

My 07 sound bad too but runs great no issues