Top end rattle around 3500-5000. Valves?

I'm getting what I can only describe as a "rattle" at partial throttle. The sound goes all the way through the exhaust - and no, it is not a rattling exhaust. I've checked the exhaust joints, and they're fine. I can hear it from the top also...

I'm assuming this has to do with valve clearances?

Is this a serious thing that needs to be fixed before I ride it anymore, or just something that needs to be done sometime relatively soon?

Thanks in advance.

 

3500 is too high for valve noise ... usually just off idle is where it soounds the loudest. I'll guess its cam chain tensioner. But no idea what this bikes CCT sounds like. So no clue. Blender full of marbles noise is what the CB honda's make ... suzuki GS and kawi ZX series bikes are quieter and more scraping like ... instead of grinding.
Cool.
Srinath.

 

Yea Dan, I'd check the camchain tensioner. It could also be the exhaust. Yea I know you checked it but you missed one thing. These bikes have double walled header pipes and when the inside pipe breaks loose it will make some racket. Only way to check is with a mechanics stethoscope.
To set the camchain tensioner remove the left point cover and rotate the engine with a 19mm wrench to the C mark. NOT the T mark. Once there just loosen the jam nut on the tensioner and listen for the click. If you don't hear it then it is most likely tight. There is a possibility that it is stuck also. If you suspect that, then remove the tensioner and clean it good. Then soak it in fresh oil and install.

 

I have a Mac exhaust on it, so I don't think the pipes are double walled.

On second examination, I can't really hear it from the top of the engine. It's more of a nasty rasping/farting/rattle exhaust note during moderate to heavy throttle.... not really like marbles in a can, but nasty sounding all the same...
Still sound like the tensioner? Any guesses?

 

Easy way to check CCT. Take off the valve cover ... put the thing in 6th pull out the spark plugs and turn the back wheel over in the forward direction while looking at the section of the chain between the 2 cam sprokets ... you see any time the chain sag ... its bad.
Cool.
Srinath.

 

Haynes says my bike has an automatic chain tensioner, and cannot be adjusted manually. I haven't pulled the cover to look at the chain, but I don't think that's the sound. It only does it at higher revs.It used to only do it at 4k, now it seems to do it in other places as well. Maybe this is just a normal noise for the pods/header. I dunno. It sounds kinda nasty

Where can you pick up the valve-measuring tool?
I think I need to check the clearances regardless of other stuff. My valve cover gasket is leaking too, so I might as well check clearances while i've got it off and replacing it....

 

Grab one of those things i see on tv over here that your famous for [longhorn] cut the pointy bit off and stick in ear and listen about , but i would take the noise seriously , first discount it is the exaust , the only other thing that sort of rattle are the cam chain or primary chain , the other noises are usually a tap tapi sound depending on rpm..

there is a cupla posts on the easyier way to guess the condition of the chains not to far back..

 

Maybe it is ignition timing? The timing is supposed to retard at higher rpms, right? If this fails, you could get predetonation, or some loss of power, right?

 

it certainly could be your cct. I replaced the tensioner and the guides to no avail on my 82 xj 750. a lot of guys told me the chain was streteched, and for it to come back to 'normal' the crank had to come out. I dealt with the noise content in what I had done. sold the bike like that, and never did have an issue with it.

another thing you might want to check would be the exhaust springs. I had a 99 f4 that I bought off a friend (I already had one) that he swore up and down had bad valves because of the noise it made around 6k. I found out that it was the exhaust springs that held the can onto the mid pipe. a couple of different exhaust springs (ones with rubber around them) and the issue was fixed. I sat the bike on a stand and revved it and that is how I found out it was the springs.

 

it certainly could be your cct. I replaced the tensioner and the guides to no avail on my 82 xj 750. a lot of guys told me the chain was streteched, and for it to come back to 'normal' the crank had to come out. I dealt with the noise content in what I had done. sold the bike like that, and never did have an issue with it.

another thing you might want to check would be the exhaust springs. I had a 99 f4 that I bought off a friend (I already had one) that he swore up and down had bad valves because of the noise it made around 6k. I found out that it was the exhaust springs that held the can onto the mid pipe. a couple of different exhaust springs (ones with rubber around them) and the issue was fixed. I sat the bike on a stand and revved it and that is how I found out it was the springs.

 

On a GS ... you could also have side ways float of Cam shafts ...
My 49K miler was side playing and noisy at 35K, it was around 1/2 mm when I first measured it ... and the damn thing never wore to 1mm in 14K ... 1mm was the thinnest shim you can get ... and it stayed at .5mm. Then I took the caps off, welded up aluminum on it, and surfaced it back down to be 1/2 mm thicker and dropped it back in, and the damn motor was quieter than it was at 8K.
No idea what it is on a XJ, we have more and better caps on the camshafts than the GS did.
Cool.
Srinath.

 

My 1983 XJ550, is experiencing the same problem. I also get a rattling/chatting noise that is most noticeable around 3-5k RPM. I notice however, that I don't hear mine until the bike starts to warm up about 5-10 miles down the road. When it's cold, it sounds fine. It's not until it warms up that things start to rattle. I tired to adjust my CCT, and it didn't appear to be any better. My bike has 18K miles, and other than this noise runs fine. I just got the bike the beginning of the summer and have had a blast riding, except for this noise. I also wonder if this isn't something I need to be concerned about.

 

Check out this link SPG500

http://xjbikes.com/Forums/viewtopic/t=1274.html

 

Thanks for the info and links. I am going to ask a dumb question, and I apologize for my lack of understanding. I know where the Cam Chain Tensioner bolt and lock nut are located. (I loosened and tightened according to the manual). My question is this. The other post you directed me to said this could be easily removed and soaked in oil. How do I do this? From what I can tell, there are two bolts that attach it. Is this all I have to do to remove it? Do I need to remove the valve cover for any reason.

I have worked on a number of cars before (simple stuff), but this bike thing is a little new to me.

Thanks so much..

Scott

 

The only dumb question is the one you don't ask.

There should be no reason to remove the valve cover. Make sure the bolt and nut are tight so it doesn't fly apart when you remove the 2 mounting bolts.
Someone mentioned the thing flying across the shop, so be careful when you do release the lock nut and bolt. and clean as mentioned in the other thread. You will need to make a new gasket for remounting.
Good luck hope thats you trouble.

 

Make sure you turn the engine to the correct timing mark as discribed in the above link.

 

Thanks so much..I will let you know how things go.

Scott
83 XJ550