03 YZ450F motor noise/rattle

[doc427]

Hey guys i've read a couple posts where you discuss the noise that these 450s make, but i just bought a bike and the noise is really loud. i have included a link, listen to it and let me know what you think. my buddy has a 426 and it has some motor noise but not like this. the guys down at the dealership said they all make noise but if there's something wrong i would like to be proactive. Also pulling in the clutch lever does not seem to affect the noise level

[qwik12beat]

I think thats a bit excesswive. Have you shimmed the valves since you got it?Its hard to seperate the engine noise from the exhaust.

[sacfelix]

My 06 started making the same noise so I checked the valves and they were ok. I next moved to the timing chain and tensioner. After I replaced them the sound disappeared completely. Well except for the usual noise they make.

[yamaha2004r6]

hey it my wr 400 started to make the same noise. i havnt found out what it is yet but have been told could be the cam chain and tensioner, i wont find out for sure untill next week as im waiting for the parts to change them and due to the xmas hoilidays the parts are taking longer than normal. im also going to get the valves checked. i hoe you sort it soon, if you want ill let you know this time next week if it sort's it out.... good luck

[TIG88]

I think thats a bit excesswive. Have you shimmed the valves since you got it?Its hard to seperate the engine noise from the exhaust.

Agreed. My 03 dosent seem to make near that much noise. You can hear little rattles and ticks and such, but that sounds like something more serious.

Change the oil and look for anything unusual.

Maybe you should take a movie with the camera pointed towards the engine. This would help seperate the exhaust noise.

[doc427]

it sounds like the timing chain and tensioner might be the problem, i have chainged the oil and filter there was a little debri stuck to the oil drain magnet but it was very minor. the guy i bought it from said he recently had the valves checked but who know what he means by recently. im definitely interested in the results that the chain and tensioner give are these parts expensive, and is it something a guy with basic tools and wrenching skills perform? I am rebuilding the carb right know and when its finished i will make another movie and try to get more of the noise and not so much of the exhaust. Thanks for your reply's guys this site is awesome.

[yamaha2004r6]

it sounds like the timing chain and tensioner might be the problem, i have chainged the oil and filter there was a little debri stuck to the oil drain magnet but it was very minor. the guy i bought it from said he recently had the valves checked but who know what he means by recently. im definitely interested in the results that the chain and tensioner give are these parts expensive, and is it something a guy with basic tools and wrenching skills perform? I am rebuilding the carb right know and when its finished i will make another movie and try to get more of the noise and not so much of the exhaust. Thanks for your reply's guys this site is awesome.

Hi mate in the UK the parts cost me £107 from yamaha and the local garage is charging me a hours labour (£30) to change the chain and tensioner and hes also checking the valves,

[sacfelix]

The parts are not expensive and is considered cheap insurance. The tensioner cost me $40 & the cam chain was $13. It was very simple to do and the only special tools I needed was a flywheel puller from tusk $15. The puller is essential and you shouldnt try any thing else.

[tnl]

Was the bike outside or in a garage? Does it go away when it's reved up? Take it outside and see if it's any quieter. My 05 had a loose kick starter shaft at the pivot that was rattling when it was in the closed position making a strange noise but yours looked secure? My vote is cam chain.

[BC3]

I would say cam chain but a seized piston makes noise also....Broken ring, clutch basket, all you can do is start checking stuff and see where it takes you.....

[doc427]

New problem... i took it up and down the street after making the video and it stalled on me, kinda felt like it ran out of gas, but there was still plenty in the tank. I fired it back up and now it will not throttle up. it will sit there and idle but if you try to get the r's up it put, poot, dies. with the choke out it performs a little better but then backfires and still dies. i took the carb apart and cleaned everything, reassembled and the problem remains. i also installed a new plug, this made no difference in the bikes performance just my wallet. im feeling a little overwhelmed and wondering if i bought a POS bike. Also the auto decompress must have failed as the kick starter was not budging, i put it in gear rocked it back and forth and it freed up and i was able to start it again, this happened several times, this afternoon. i read in a post-it thread that it could be a cam issue, so maybe that is my problem but does that explain the throttle issues as well? i just don't know enough about these bikes and they seem more difficult to work on than my 1985 yz 250.

[qwik12beat]

Well it seems that your camchain, and tensioner may be making the noise. If they are that far out of spec to make that much noise your cams may have jumped time. Id pull the valve cover and timing plugs, and confirm your timing first.

[MAD_POTTER]

Pull the side cover and check your primary drive gear. My drive gear nut came loose allowing the folding tab washer to vibrate and disintegrate which in turn allowed the nut to back off more until it ground away at the inside of the side cover. My 03 always made lots of noise until I fixed this problem and now it's noticeably quieter. My bike did the same thing, stalling for no reason, then there was a lot of drag on the kickstarter like it had started to seize and then the kickstarter wouldn't move at all. Pull your oil filter and see if it's full of aluminum shavings. If so check the gear and nut. Good luck!

[BC3]

Well it seems that your camchain, and tensioner may be making the noise. If they are that far out of spec to make that much noise your cams may have jumped time. Id pull the valve cover and timing plugs, and confirm your timing first.

I have listened to the noise and agree with qwik12beat...I think the chain was so loose that it jumped time and now that's why it is hard to kick and won't run above an idle....Has some ear markings of a carb problem but would definitely check the cam timing before doing anything else

[doc427]

i pulled the valve cover to try and determine if the chain is bad, it does not feel loose to the touch. there is some movement in it if i grab it and shake it up and down approximately 3/8 of an inch play. is this normal? the motor is also conflicting with my service book. the book states that the far right side cam lobes should be opposite of each other when the motor is at TDC, but with mine the are pointing in at each other, also the marks on the cam sprocket that the chain rides around are pointing at each other and the book says they should be on the other side inline with the top of the head. If things are that far off, would the bike even run? i have two books and they both say the same thing about the lobes and marks on the gears. i noticed there was an after market flywheel weight on the bike so i though maybe the mark to line up TDC might be off but there is no time while rotating the flywheel weight that the lobes or gears match what the books are saying. Any input would be appreciated.

[grayracer513]

the motor is also conflicting with my service book. the book states that the far right side cam lobes should be opposite of each other when the motor is at TDC, but with mine the are pointing in at each other, also the marks on the cam sprocket that the chain rides around are pointing at each other and the book says they should be on the other side inline with the top of the head. If things are that far off, would the bike even run?

You're checking the timing on the wrong stroke. The crank rotates twice for each revolution of the camshafts. The cams will be correctly oriented if you turn the engine over to the next TDC.

Read:

http://en.wikipedia.org/wiki/Four-stroke_engine

Look at the 1st and 4th of the 6 still images showing the piston at TDC, and note that the cams are in opposite positions.

If the mark on the flywheel is suspect, remove the spark plug and probe to the piston crown to locate TDC. Then, check the timing marks.

[doc427]

You're checking the timing on the wrong stroke. The crank rotates twice for each revolution of the camshafts. The cams will be correctly oriented if you turn the engine over to the next TDC.

Read:

http://en.wikipedia.org/wiki/Four-stroke_engine

Look at the 1st and 4th of the 6 still images showing the piston at TDC, and note that the cams are in opposite positions.

If the mark on the flywheel is suspect, remove the spark plug and probe to the piston crown to locate TDC. Then, check the timing marks.

well i feel like an idiot, i should have been able to figure that out. The spark plug trick worked better than the mark on the flywheel. the lobes and the marks on the gears are very close to being identical, but i don't think they are perfect. does this mean that the chain jumping a tooth theory might be in fact true. how does a guy go about making them perfect is it done by the eye, and again how tight should the cam chain be? As i mentioned before if i grab the top of mine with two fingers i am able to move it up and down a good 3/8-1/2 inch total travel back and forth. This does however take some force to do it's not like the drive chain. to me it seems like it would be hard for it to jump a tooth

[grayracer513]

the lobes and the marks on the gears are very close to being identical, but i don't think they are perfect. does this mean that the chain jumping a tooth theory might be in fact true. how does a guy go about making them perfect is it done by the eye, and again how tight should the cam chain be? As i mentioned before if i grab the top of mine with two fingers i am able to move it up and down a good 3/8-1/2 inch total travel back and forth. This does however take some force to do it's not like the drive chain. to me it seems like it would be hard for it to jump a tooth

The marks are rarely perfect. The question as you look at them is whether moving them one full tooth either way would make them look closer or not. OTOH, if the bike has never had a timing chain, it's time it did.

The cam chain should have no actual slack in it. What you describe is pretty much normal.

[doc427]

So i have posted a few links to some pics of the cam lobes and cam sprockets. I am also going to go ahead and replace the chain tomorrow. does the tensioner always need to be replaced? i was thinking i could run it through the test specified in the manual and if it checks out OK, reuse it. is this acceptable? the cams do not line up perfectly but like grayracer513 said they almost never do. do you guys have any other suggestions for the rpm problem, it will idle but if you try to give it any throttle it dies.

http://c1.ac-images.myspacecdn.com/images02/62/l_61640964c63640b98decb8937dcabdbc.jpg

http://c1.ac-images.myspacecdn.com/images02/9/l_9e1c7a0db43249c08f984815a21b0980.jpg

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http://c2.ac-images.myspacecdn.com/images02/58/l_ea396d5607864aa7bf1a58991045832d.jpg

[leoninlux]

hey mate i have an 07 YZ450 and it makes a similar noise but not as bad, only it seemed to get quieter when I pulled my clutch in, so I took out my clutch friction plates and noticed that my basket was totally mashed as if it was 10 years old or somethin, a quick look at your clutch basket will eliminate this!