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-   -   Question about CRF450 top end noise (http://www.allthingsmoto.com/forums/f-19/question-about-crf450-top-end-noise-5320/)

4504ever 11-19-2003 11:45 PM

Question about CRF450 top end noise
 
Hello everyone,
This is my first time in this forum and it looks like i finally found what i've been looking for,lots of good information.I just bought a new 04 CRF450 and think it is a great bike .So far i've only rode it around the house so i haven't had a real chance to test it out fully.My question is that i was wondering about the top end noise that it makes .Its not a bad noise it just sounds like a muffeled rattle, mostly at a idle.I've been riding dirt bikes a long time just mainly 2-strokes.This is my first high-performance 4-stroke i've owned or even heard run up close.So i wanted to ask other 450 owners if there bikes are a little noisy .I'm probally just being paraniod but i thought this might be the place to ask.This weekend i will get to go on a full day ride and i can't hardly wait.
thanks for any comments...........Mike

cowboyona426 11-19-2003 11:52 PM

Re: Question about CRF450 top end noise
 
First off- WELCOME TO THE SITE! Enjoy your stay here and don't hesitate to ask any questions. To answer your question- it's normal, don't sweat it. Just think of how much stuff is moving around in there and it will make sense :thumb

Woody_393 11-20-2003 12:14 AM

Re: Question about CRF450 top end noise
 
The noise your talking about it more than likely your chain (not the chain for the valves, but for the rear wheel).

If your chain is too loose it will slap against the chain guard which in turn slaps against the swing arm making all kinds of racket. It does sound like it it coming from the engine though.

You may especially notice it when the suspension is compressed a little, since the more compressed it is, the looser the chain will become.

Tighten you chain up a bit and it should go away.

I like to tighten it to the point that I can get a tight 3 fingers in between the swing arm and the chain just after the chain guard ends.

On a new bike with the rubber band chain, you'll be tightening all the time. If you have the cash I'd get a good O or X ring chain right now so you get good life from your sprockets.

Oh, and welcome to ATM. Glad to have another CRF guy.

cowboyona426 11-20-2003 12:18 AM

Re: Question about CRF450 top end noise
 
Woody- I don't think it's the chain- he said the bike makes this sound at an idle. Me thinks it's a 4 stroke newbie (no offense kodiakkool) hearing vavles and cams moving around inside the motor, and I'm always right :rolleyes:

Woody_393 11-20-2003 12:29 AM

Re: Question about CRF450 top end noise
 
Hmm, appears to be that you are right. BUT, I don't recall any sound from my CRF??? Not that it doesn't make sound, but I've never noticed anything out of the ordinary from the engine.

zoohoot393 11-20-2003 12:39 AM

Re: Question about CRF450 top end noise
 
Me neither, and I also have an '04.

Woody_393 11-20-2003 12:57 AM

Re: Question about CRF450 top end noise
 
Does it sound like maybe the valves? I guess they could come out of spec???

If you noticed it, and it's bothering you, I would take it to the dealer and have them take a look. A new bike should not make out of the ordinary sounds.

4504ever 11-20-2003 09:10 AM

Re: Question about CRF450 top end noise
 
Maybe this sound is ordinary.I haven't had a chance yet to listen to any newer 4-strokes up close .maybe this weekend.The bike runs and starts good so if the vavles were out wouldn't that effect the way it srarted and ran.I would like to think like that cowboyona426 was right and its all the parts up top moving that i am hearing .If you are standing next to your bike without your helmet on you guys can't hear any noise coming from your top end at all ?I'm not trying to be a pain but this is the first bike i have spent 6000.00 on and i guess i'm being a little picky.I talked to the dealer and he told me it was normal to hear more top end noise then like what my old XL250 made.Just wanted to hear from some actual owners to see what they thought.Well got to go to work.I'll check back tonite ......Have a good day....Mike

TexTwister 393 11-20-2003 09:13 AM

Re: Question about CRF450 top end noise
 
Remember anything below 800 to 1000 rpm the auto decompresor will make noise, thats probably what you are hearing cause it goes away when you give it some gas right?

MATTXR250R 11-20-2003 10:33 AM

Re: Question about CRF450 top end noise
 
Ok if I am not mistaken the CRF unlike the YZF's uses 2 rocker arms to open the exhaust valves.

If you have ever stood beside a Honda XR without your helmet on you will hear a tapping noise..kinda like a tick. On an XR this comes from the valve tappets making contact with the sub rocker arms. I know the CRF doesn't have tappet adjusters on the rocker arms but trying to make a point here. On an XR the looser the valves are the more "Valvetrain"noise you are gonna hear because the tappet has more cleareance between it and the sub rocker arm. The YZFs don't have any rocker arms so I think in turn it would be a little quieter than the CRF as its using the cam lobes to open the valves. On the CRF you will hear more noise I think because of the 2 rocker arms for the exhaust valves. Some little ticking sounds coming from the topend of a 4-stroke is completly normal. Think you want to listen for is a slapping noise which is the cam chain wore out and slapping the cases but this is not your problem as your bike is brand new...ride that baby and HAVE FUN!

**EDIT**I thought I was correct about the Rocker arms on the CRF as you can see .HERE



Congrats on the CRF BTW

smithers 11-26-2003 09:57 AM

Re: Question about CRF450 top end noise
 
Yeah, Ive noticed my CRF is noisy..It isnt a clankety clankety sound...more like a whiring...Its the valve train. I noticed it first thing also and ive been on two strokes all my life as well. Watch your filter and oil when you change it...if theres excessive amounts of metal in there, better haul it to the shop...if not ride on and have fun!

MATTXR250R 11-26-2003 10:58 AM

Re: Question about CRF450 top end noise
 
That whriling sound on 2-strokes is usually the waterpump impellar..I know you can hear it pretty good on my CR..the whriling on your CRF Smithers also might be coming from the impellar..some of it anyways..

Good point on the oil and filter as Smithers mentioned. when I would change the oil and filter on my XR I would cut the filter in 1/2 to really check it good.

Yardpro393 11-26-2003 11:33 AM

Re: Question about CRF450 top end noise
 
matt
the crf has one rocker arm that splits into two arms for the ehxaust valves.

i rode an 04 with a skid plate installed. the skid plate reflected alot of rattle noise so i could hear it. it made me nervous enough i took the bike back to the guy and asked about it.

Motomom 11-26-2003 11:52 AM

Re: Question about CRF450 top end noise
 
If it's still under warranty and you are unsure - take it back and let the dealer look at it. They may have to do a few adjustments to the valves or cam chain. If it's just adjustments, mosts dealers will do it for free. Good luck.

MATTXR250R 11-26-2003 11:56 AM

Re: Question about CRF450 top end noise
 
Motomom...no adjustment to the cam chain is nesacerry(sp?)as the CRF has an automatic cam chain tensionor..same with the XRs,etc.

smithers 11-26-2003 12:09 PM

Re: Question about CRF450 top end noise
 
No warrenties on the CRF that I know of, and ya know YP has a point...I have a big ol skid plate on mine and it sure resonates sound when a rock hits it...sounds like the gong show. Bet that would account for extra engine noise also.

Woody_393 11-26-2003 09:22 PM

Re: Question about CRF450 top end noise
 
Yeah, I didn't even think about that. I have heard a lot of guys say their skid plate really makes the engine noisy.

Xktmracer 01-05-2004 07:18 PM

CRF low RPM rattle
 
My friend and I just purchased '04 CRF450's, and at low rpm the bikes make a hell of a racket. Oh, and for the record, the CRF is not my first four-stroke. I've owned an XT200, a KLR250, a DR350, two DRZ400's, a 520SX, a 525EXC, and a number of 4-wheelers. Our CRF's rattle loudly at low rpm. This dissappears as the revs climb. We both suspect that the cam chains are too loose. Anyone else have the same idea?:gas

Shifting 01-05-2004 08:45 PM

Re: Question about CRF450 top end noise
 
First off, welcome to ATM. My CRF makes some noise at low low rpm's. As far as the cam chain being loose, I don't really know. Never had an ounce of problems with the top end. About 40 hours on her and never had to adjust the valves, although I checked my clearence regularly. I have a hard time thinking you both got machines with the same problem and I have never heard any one else say anything about the "excessive" noise from the 04's.

Anyone else ...

Woody_393 01-05-2004 08:47 PM

Re: Question about CRF450 top end noise
 
It isn't possibly the chain slapping on the plastic (or whatever material it is) on the swing arm is it? It does sound similar to what a cam chain would sound like.

It usually means the chain (the final drive one that is) is too loose.

Could that be it? It certainly does make a racket when it slaps.


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