Help Diagnose "clunking" noise
#11
06-08-2010, 10:40 PM
Join Date: Jun 2010
Location: Charleston SC
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
thanks
justasquid,
Thanks for all good info! I will try the things you said. I have always been one who leans to the side of caution. "an ounce of prevention is better than a pound of cure", so I wanted to make sure it wasn't something that is going to get worse when I could fix it now. Thanks again for all of your help! I will keep you posted.
Thanks for all good info! I will try the things you said. I have always been one who leans to the side of caution. "an ounce of prevention is better than a pound of cure", so I wanted to make sure it wasn't something that is going to get worse when I could fix it now. Thanks again for all of your help! I will keep you posted.
#12
06-09-2010, 05:35 AM
It looks normal to me, aside from the chain seems a bit too loose. But you have to remember, your rear wheel has no resistance at all, so as your rpms go up and down at ilde, the slack is constantly changing with in the chain. basically, when the engine is pulling on the chain, the top portion of the chain is under tension, the lower portion has the slack. When the rpms drop, the tension and slack swap sides. the rear wheel still has momentum, but the engine has slowed, so you get the jump in the chain. Remember, this is all happening very fast as the idle lopes. the noise your hearing is the rear sprocket catching up to and putting tension on the lower portion of the chain, then when it catches, it slows, then the front sprocket pulls on the rear again. You don't feel this when the bike is on the road because the rear sprocket can't catch up to the front sprocket.
For example, with the bike off and in netrual, spin the rear tire and stop the tire from spinning really fast. You will see the chain jump and clunk. Also, as fast as you can, rotate the wheel back and forth, as this is what is happening when the bike is on the stand. And since the bike is neutral, you know its not internal to the engine.
If your still unsure. tighten the chain until just until there is no slack to where you can barely move the chain up and down. DO NOT overtighten the chain though. repeat the same process you just did and I will bet your problem will not be there. BUT......... make sure you put the correct tension back into the chain after the test. you don't want to ride on an overtightened chain as it will put too much stress on the output shaft bearing. But for this test on the stand, it will be fine.
Having said all this. Kuroshio brings up a valid point in that you should aslo check to make sure your master link did not get over tightened. Loosen the chain completely and make sure you can move the masterlink up and down easily without it sticking.
Another thing, is to make sure your cush drive is not damaged. If you not sure what that is, its the rubber drive cushions that are mounted behind your sprocket. they are pie shaped pieces of rubber that isolate driveline impacts.
but all in all. I think your chain is a bit loose, otherwise, normal when on a stand.
For example, with the bike off and in netrual, spin the rear tire and stop the tire from spinning really fast. You will see the chain jump and clunk. Also, as fast as you can, rotate the wheel back and forth, as this is what is happening when the bike is on the stand. And since the bike is neutral, you know its not internal to the engine.
If your still unsure. tighten the chain until just until there is no slack to where you can barely move the chain up and down. DO NOT overtighten the chain though. repeat the same process you just did and I will bet your problem will not be there. BUT......... make sure you put the correct tension back into the chain after the test. you don't want to ride on an overtightened chain as it will put too much stress on the output shaft bearing. But for this test on the stand, it will be fine.
Having said all this. Kuroshio brings up a valid point in that you should aslo check to make sure your master link did not get over tightened. Loosen the chain completely and make sure you can move the masterlink up and down easily without it sticking.
Another thing, is to make sure your cush drive is not damaged. If you not sure what that is, its the rubber drive cushions that are mounted behind your sprocket. they are pie shaped pieces of rubber that isolate driveline impacts.
but all in all. I think your chain is a bit loose, otherwise, normal when on a stand.
One other thing that can cause the noise, is if the chain isn't properly clean and lubed..I suggest, if you ride alot (400-500 miles a week) that you do the chain weekly (I ride about that)give or take. Noticed my chain doing the same thing, cleaned it, waxed it, and the issue went away...Good luck mayne 
BTW, not sure what the slack is supposed to be, but, most of the bigger bikes today with good suspension travel seem to require roughly 1.75 inches of play as a max, I wouldn't go under 1.25, as was mentioned earlier, bad on the output shaft
#13
06-12-2010, 09:02 AM
Join Date: Jun 2010
Location: Charleston SC
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
Clunk still there
Thanks everyone for the helpful advice. Unfortunately, the noise is still there and it is definitely coming from behind the drive sprocket area. I will check again today to see what shape the cush drive pads are in, but when I replaced the front sprocket recently I didn't see anything that stood out as bad. I have a bad feeling the noise has something to do with the transmission, but I have no idea what it could be. It does seem to be getting worse, it seems louder today after a short ride last night. I don't have a very good selections of repair shops to choose from around here, and don't want to get ripped off by taking it in and them telling me some. B.S... Thanks everyone.
#14
06-14-2010, 03:35 PM
Senior Member
I'm in the same boat right now. I have my chain off and I hear the same noise from the front sprocket. If I put it in Neutral (the front spins a bit too of course cuz of clutch pack) or if I pull the clutch in while in gear, there is no noise. As soon as I let the clutch go in gear I hear the clunking. It is definitely in the shifter side, and it goes with the RPMs while in gear. It had a moment where it didn't do it after I was clickin the gears around gettin to neutral while the bike was off, but when I turned revved it a bit in gear it came right back.
It does cycle through all gears just fine too, just obvious somethin is messed up.
The other day my chain ended up being loose and came off binding between the swing arm and the rear sprocket. My swing arm, rear sprocket and of course chain are toast now cuz of this. This happened while I was exiting the freeway still at about 65mph, so it got some good abuse while rolling off the exit. Fortunately I have an extra swing arm and the portions that are messed up can be fixed with TLC.... WTF! So far it's most likely a bent/busted shift fork and a probable chance for me to disassemble the engine.
If I was you, I'd get that chain off and test it out. If your chain is good just pull the rear wheel and sprockets and figure out what to do with the chain. As long as the chain isn't going to rotate when you put the bike in gear you can see if you hear the noise still. If you do, I think you have a pretty good idea as to what you'll be doing next. In my case I'm getting a bottle of Jack and waiting for my axle, brakes, and gears for my truck to be shipped so I can install them next week, then look forward to exploring an area of the motorcycle I only dreamt of seeing. I'm sure there will be several bottles of Jack in between those days/weeks/months. :\
It does cycle through all gears just fine too, just obvious somethin is messed up.
The other day my chain ended up being loose and came off binding between the swing arm and the rear sprocket. My swing arm, rear sprocket and of course chain are toast now cuz of this. This happened while I was exiting the freeway still at about 65mph, so it got some good abuse while rolling off the exit. Fortunately I have an extra swing arm and the portions that are messed up can be fixed with TLC.... WTF! So far it's most likely a bent/busted shift fork and a probable chance for me to disassemble the engine.
If I was you, I'd get that chain off and test it out. If your chain is good just pull the rear wheel and sprockets and figure out what to do with the chain. As long as the chain isn't going to rotate when you put the bike in gear you can see if you hear the noise still. If you do, I think you have a pretty good idea as to what you'll be doing next. In my case I'm getting a bottle of Jack and waiting for my axle, brakes, and gears for my truck to be shipped so I can install them next week, then look forward to exploring an area of the motorcycle I only dreamt of seeing. I'm sure there will be several bottles of Jack in between those days/weeks/months. :\
Last edited by entity-unknown; 06-14-2010 at 04:07 PM.
#15
06-14-2010, 05:46 PM
Senior Member
Looking into this, it's likely the shift forks, drum, and/or the clutch which are probably what's shot in yours and my bike. They're fairly easy to fix if you've done some moderate mechanic work before. You just gotta be careful and take your time. The engine may have to come out for the forks and drum but you flip it up side down, pull some stuff off (the manual covers it well) and they're coming out. You can visually inspect everything when the oil pan is removed. From here you should have a decent idea as to what needs to be replaced. The clutch should work out the same with the cover off. It was time to do an oil change anyways right? If it's the barrel and shift forks, looks pretty simple even according to the book. The clutch I think is a bit harder but still easy. If it's the gears, you'll have to decide on that one yourself. I'd do it, but that's just cuz I like this stuff. The last thing to think about is you're still riding it. If you keep on, your gears will definitely go if they haven't already not to mention something else may happen to... you. It'd sure suck for that gear box to go in the apex of a lean... Just some food for thought.
Last edited by entity-unknown; 06-16-2010 at 12:39 AM.
Thread
Thread Starter
Forum
Replies
Last Post
KenG
CBR1000F For Sale / Found
7
08-09-2009 05:20 AM
