Slight Knocking Sound

[Newell33]

Hi Guys

My 2007 FZ6 with 9,000 miles has a slight knocking sound coming from the engine when it's warm. It does it with the clutch in and out, and while in and out of gear. The noise is barely noticeable when the engine is cold, and it gets more pronounced as the engine temperature increases. I've searched before on this site, and found a thread or two describing and showing videos of the exact same noise, but none of the original posters every replied and said that they had resolved the issue. Below is a link to a video that I found online of the exact same noise. My noise isn't near as bad as the one in the video, but it's definitely the same noise. When I first got the bike I thought maybe it was a clutch or clutch basket issue, so I replaced the clutch discs and changed the fluid (nothing looked out of the ordinary). The noise is still present.

[ame="http://www.youtube.com/watch?v=1QAfAWUxVOo"]YouTube[/ame]

Has anyone else on this forum every had and resolved this issue?

Thanks in advance for the help!
Josh

 

[FinalImpact]

Get a long wooden stick and listen to the top of the engine. The bottom at the crank and then the rear at transmission from both sides and the back.

Also, cut open the oil filter and look in the pleats for anything grey like a bearing. Copper would be easier to see, but once at the copper level of a wear its pretty loose and will knock if its a rod bearing. Main bearings usually only show under load and with an obvious drop in oil pressure due to leaking internally. At copper stages of rod bearing wear they knock pretty loud.

Not sure what to make of the video. Look for some Rod knock videos and see if they sound the same.

 

[Newell33]

Thanks for the response. The rod knock videos that I've watched for these bikes do appear to sound different. They seem to knock with more frequency than the sound coming from my bike, and the noise for that type of problem seems to be more pronounced at idle as well. It has me a bit stumped. I think cutting the oil filter is a good idea, so I'll try that and see what I find.

 

[TownsendsFJR1300]

Sending off a sample of the oil for analyses should help reveal what's going on inside your engine.

It doesn't sound good. Obviously a rotational part likely from the engine, not transmission.

On an FJR fourm, (could have been here) someone had a noise similar.

To help narrow it down, they pulled the clutch plates out (disconnecting the transmission from the engine itself). If the noise stopped, it was in the "engine side" of things, not the transmission.

If I re-call, the oil pump chain runs off a gear on the back of the main clutch, so running W/O the plates, shouldn't be an issue for the oil pump , correct? They actually ran the engine with the clutch cover off, very little, if any, oil splattered out..

If you can do your own video/audio, try to narrow down the area.

What were you oil change intervals, any recent work done to the bike?

Also, for the op, do (or have done) an oil pressure test and see if your within spec's

 

[TownsendsFJR1300]

As I re-call, with the oil pan off, you do have some access to the lower connecting rods. When that noise gets bad enough (unless you tear down before hand), pulling the pan would likely give you an idea if the lower rod bearings are toast.

 

[FinalImpact]

[ame="http://www.youtube.com/watch?v=1QAfAWUxVOo"]YouTube[/ame]

Listened again on different speakers - So, you replaced the clutch discs. Tell me about the color and any details from old to new. Did you use Yamaha parts? Did they look the same?

Off hand, it sounds a lot like the clutch disc through the crank/clutch drive gears. Its not a 1:1 engine speed. Each cylinder only fires every other go round so it could be rod, but that wooden stick would help you find the wear part. Even an old toilet plunger handle would work for some.

Another trick is pull up each plug wire one by one. Throw an old plug in the cap and rest it on the header. Fire it off rev it ever so slightly. See if each one sounds the same.

One guy ran his with NO oil pump as the driven drum (clutch housing) was removed. As stated, you could remove all the friction and steel plates and see how it sounds after the wooden stick, plug, and filter exam.

Just thinking out loud.

 

[Newell33]

YouTube

Listened again on different speakers - So, you replaced the clutch discs. Tell me about the color and any details from old to new. Did you use Yamaha parts? Did they look the same?

Off hand, it sounds a lot like the clutch disc through the crank/clutch drive gears. Its not a 1:1 engine speed. Each cylinder only fires every other go round so it could be rod, but that wooden stick would help you find the wear part. Even an old toilet plunger handle would work for some.

Another trick is pull up each plug wire one by one. Throw an old plug in the cap and rest it on the header. Fire it off rev it ever so slightly. See if each one sounds the same.

One guy ran his with NO oil pump as the driven drum (clutch housing) was removed. As stated, you could remove all the friction and steel plates and see how it sounds after the wooden stick, plug, and filter exam.

Just thinking out loud.

I got the bike with about 7,800 miles. I didn't notice the noise at first. It seems to have gotten a little worse over the last 1500 miles or so. When I started to hear it, I looked around online. Someone on one of the forums mentioned a similar noise caused by broken clutch discs, and maybe a bent clutch basket. I then ordered a Barnett clutch kit and installed it. The basket was in great condition, and the clutch discs that I pulled out appeared to be in good shape. I don't remember what they measured, but they were still within the allowable limit. I was hoping I would find something visibly wrong, but I didn't. The noise remained the same after the clutch kit was installed.

I'll do some more playing around with it this weekend and see what I find.

Thanks guys!

 

[FinalImpact]

^^ More specifically; Does it look like anyone was ever in there before you? Any bolts rounded, extra sealant, any tell tale sign that someone may have already replaced those fiber discs?

 

[Newell33]

^^ More specifically; Does it look like anyone was ever in there before you? Any bolts rounded, extra sealant, any tell tale sign that someone may have already replaced those fiber discs?

I didn't see any signs that anyone had been in there before. Everything looked factory and unmolested.

 

[TownsendsFJR1300]

I did some searching yesterday.

Another member had the same noise, couldn't find it and traded it in and never knew what the issue was except that the oil pump chain was very loose.

If you have the clutch cover off, (trying to remember), you'll see that chain, very short, rearward of the clutch and down. There is no tensioner on it and there is no spec for tightness. Anyway, look around that chain area to se if its loose, possibly rattling against the engine case, etc.

It can be replaced with the pan removed and the clutch pulled if replacement is needed. ( I'd be surprised if it was that loose with the low miles)

2007 Yamaha FZ6 (FZS6W) Oil Pump | Babbitts Online

 

[FinalImpact]

JM2C but an oiled chain is the least likely component to make a noise like that. If too tight or making contact, yes they can make noise.
Contact = cutting whirring sawing grinding sounds.

I recall the conversation and said the same thing then. The chain is just too small to make that kind of noise. Time will tell i guess.

Running it with clutch discs out, should tell you more. So what oil is in it??
Practice what you preach, Cutting open your OIL FILTER

 

[Motogiro]

It reminds me of cam chain noise. Wonder if it's the Cam Chain Tensioner? The FZ6 is also known for this. Mileage doesn't suggest there would be that mush wear in the chain and guides but those auto tensioners are known for giving up.

 

[TownsendsFJR1300]

Well that noise has been documented before, unfortunatly, the bike was traded in with no answers...

I agree thou, pulling the clutch plates and running would eliminate the transmission (or not).



I would definitly send the oil out for analysis.

 

[Newell33]

It's been a while since I started and visited this thread. Last year I purchased and installed a manual cam chain tensioner in place of the factory tensioner as some had suggested. I'm happy to report that the noise is no longer present. I'm not sure there's ever been any resolution on any of the other threads that I had found, so I wanted to be sure to reply here to pass along the good news. If your bike develops a similar sound, it's very likely it's the cam chain tensioner.