Bad clunking!

Hi guys,

I recently went on a 200 mile trip to my brother's house (where I am now) and as soon as I got off the highway and into town, my bike has been clunking.

The symptoms are clunking under these conditions:
-only when riding (not while in neutral, not while in first with clutch held in)
-not while accelerating (the clunking is worst when sustaining rpm's and moderate when slowing rpms)
-Seems to go with wheel spin, not engine speed


This has brought me to the conclusion that it must be something with the chain. How do I check for slack?

(92 xj600 secaII)

 

Just a wild guess... Have you checked the chain to see if it is binding anywhere? Sounds like there is some slack (I would guess there is a precise measurement of how much in the service manual) and the chain is binding at some point and slapping.

Have you tried lubing the chain? It's been a while since I messed with bike chains, so just tossing out some ideas.

 

Thank you, I don't have the manual and the internet gives no answer as to how to tighten chain or how to measure it's tension. I'm about to pull off the cover over the front sprocket the chain goes on and see if there is some obvious way to tighten it (am I supposed to move the back wheel back?).

Also I need to add that the chain 'whirr's on one side of it. (like it will whirr and then smooth then make a whirr noise again then smooth, probably because I sprayed chain lube on it while it was parked and didn't get some of it lubed - will go do that now)

 

Get a book!

You adjust the chain by loosening the rear axle and moving the wheel back. There are chain adjusters ("axle pullers") on each side; they have a small index mark in them. There are a series of marks cast or machined into the swingarm; be sure the marks on the chain adjusters line up in the same relation to the marks on both sides of the swingarm, to maintain rear wheel alignment.

Chain should be adjusted at its TIGHTEST point; rotate the wheel and check the chain in many different spots to determine the tightest point.

Adjust so it has about 40mm-45mm (1.5"-1.75") total up and down free play. This may not be the EXACT spec for your bike but it will certainly work. Be sure to keep the rear wheel aligned using the marks.

EXAMINE the chain carefully for a broken/missing roller, that could be your clunk. If the chain is fine, pull the front sprocket cover and inspect.

How many miles on the bike? How many of them are YOUR miles? How long did it sit? Does it have a drum or disc rear brake?

 

Bigfitz...I love you lol

It has 38000 miles and about 700 miles are mine. The rear brake is disc and not rubbing. The chain only has about an inch of total play in it (when I pull down on it as hard as I can it moves an inch, and then I can pull up on it as hard as I can and get an inch out of it). Just looked over whole chain, no missing rollers (if the roller is the cylindrical thing that holds links together). Should probably add that the clunking feels like it's coming from under me, or in front of me when I'm riding. Made me think there was something wrong with my front tire, but I found nothing... Will add that I bled the front brakes recently and have been using them more than before, could the pads be going out? Would that cause a clunking? I don't know how to check pads either

I promise as soon as I get some money, I will buy that Clymer.

 

have your bro or you ride past each other on the bike with the chain cover off and try to see whats going on in there... see if it gets louder with the cover off maybe... It sucks being stuck somewhere due to your vehicle !

 

Schmauster, I am staying with him for the Summer so it's no sweat but I do need to go find a job. Like right now. And my rent payment was fixing his car for him and I can't go get the part he needs (igniter) without the bike. So....I'm just going to have to deal with the clunking for today lol. I'm off to find a job, after I get back, I'll wrip it apart and figure out what that clunking is!!

 

try leaning over and listening to different sides of the bike while its doing it, you might be able to track it down a little closer. Does it do it if you roll it by hand? Do you have a center stand?

Just curious what brand / type of tach is it? I have been looking for a cheap replacement that can handle our ignition

 

Schmauster, it is a 92 so I dont think it will be the same tachometer but it is stock so....

Just got back from riding and got some more info. It does it in all gears at 4000 RPM at the same rate. Meaning if I'm in second gear at 4000 rpm the clunking is at the same rate as when I'm in fifth gear at 4000 rpm. Also, there is no clunk while engine breaking or accelerating. So, I'm thinking, it certainly is the chain or sprockets, right?! I looked a little closer at the back sprocket and noticed that just about every other tooth on it is rounded down to a hill instead of a point. Should I go open up the front sprocket cover and see what's going on? I'm not going to do it until I know I have to because I finally got my gear shift lever to stop falling out and you have to remove it in order to take that cover off...

PS Scmauster, it does not do it if I roll it by hand (or it's not noticeable). If I coast down the street with the clutch in, it will do it. I wish I had a center stand.

 

The speed-to-rpm thing defies your conclusion about the chain and sprockets. 4000rpm in second will result in a lot slower chain/sprocket speed than 4000rpm in 5th. Chain/sprocket speed correspond to wheel/road speed, nothing else.

COASTING down the street with the clutch in, and it will do it. Are you turning 4K while coasting too?

If it does it coasting with the clutch in, it does point to the chain and sprockets. "Rounded off" sprocket teeth are representative of a potentially very dangerous situation.

I STRONGLY RECOMMEND you STOP riding this bike immediately until you figure out and correct the problem, and get the chain and sprockets taken care of. If the chain breaks at speed, not only can it come up and absolutely wreck your motor; it can drop you on your butt in a NY second too.

 

Bigfitz, I will immediately stop riding (unless it's up and down the street to test clunking) and will go pull off the front sprocket cover. I will report my findings as soon as I have done that! Also, maybe I'm dealing with two different clunkings? I'll actually time out the clunkings at rpm's to make sure it's exactly the same rate (if it is does that mean it's something to do with my engine?).

 

Ok, tested it, it does it at the same speed at similar rpms in different gears. When it cools down a bit, I'll take off the sprocket cover and report back to you what I find.

 

with the bike on the sidestand in neutral grab the back sprocket and twist it back and forth (same direction the chain would pull it) and check for play
there's rubber cushions between the sprocket and the wheel that might be worn out

 

Thanks Polock and everyone else, but I figured it out! I should have pulled that cover in the first place. There's a nut threaded on to the outside of the front sprocket, well when I pulled the cover off, it fell right out. Guess I didn't put it on tight enough before lol ! Well, I'm gonna crank it down as hard as I possibly can once the bike cools down. Thanks again guys!

 

Glad you found it I would advise torquing to the correct spec. You can tighten too much on some components.

 

glad you found your problem, but since you mention it, i was under the impression that this situation would be considered 2 inches of free play. 1" down + 1" up = 2"

am i wrong here?

 

Sounds like you may be missing the lock washer for the drive sprocket.

 

RPGOERLICH, what is that?

I just went to put that nut back on and guess what?! The threads inside the nut are worn down to the point that they will screw on to the bolt, but they won't grab the back of the threads! So it won't get tight at the end... like it will turn and you can feel it click off the end of the threads and tighten it about half a turn and click ... another half turn and tight....click loose again. Make sense? That's the best way I can describe it.

That washer... if I had that, would it go on between the nut and the washer? Cause if it did, it would give me something to crank the nut down on. That would make my life 100% better right now!

 

That would be #24 in the pic.

 

UGH! I need 24 lol

Where can I get this? Dealerships don't have anything for my bike (it's too old for them)...

 

Yamaha pn 90215-23265-00 WASHER, LOCK is still available from Yamaha for a whopping $2.97.

If your local dealer doesn't have it (and they probably will in this case) you can order it from a lot of different sources online, but the shipping will eat you.

That part is still in use (in the 2009 XT250) and has been used in Yamaha street bikes, dirt bikes and ATVs since before your bike. Since it gets replaced anytime the sprocket gets changed, it's a common use item and the dealer probably will have it.

But you need more than a lock washer. You need a new chain and both sprockets PRONTO.

 

BigFitz you are the bomb. I figured that part was unique to my bike and gave up on it, I have so little patience... I'll get on the sprockets, but why do I need a new chain?

 

Because your sprockets are so worn. They didn't get that way by themselves, the chain wore them out. (Neglect might have helped.) While the chain was wearing out the sprockets, it got worn out too.

Trust me on this, I've been riding chain-driven street bikes for 44+ years and all 3 of my bikes are chain drive now.

The chain and sprockets should always be treated as a set; if you don't replace the chain your new sprockets will wear out pretty quickly too.

 

Oh. Okay, I trust you BigFitz! I'll get on the sprockets and chain! Thanks for all the help.

 

Shoot. Sorry for the bump, but I have a very crucial question to ask. Can I ride up the highway 200 miles without that lockwasher on the end of the front sprocket? I was riding around before and nothing catastrophic happened... The thing is I have an appointment at BAMC in San Antonio on monday and there's no way I can get that washer before then. I have no other way of getting up there, and I can't really miss that appointment.

 

what you CAN do and what might be safe to do are two very different things. riding with a component like that can result in catastrophic failure. the sprocket is not tight, therefore is most likely wobbling at speed causing the clunking you refer to, which would make it very easy to flip a chain, which is bad. flipping a chain can result in best case scenario, nothing, worst case scenario, cracked engine case or bodily harm (a chain hitting you in the back or leg at that speed could potentially remove body parts). i would strongly advise against riding it at all without the nut tight. now, as for obtaining a lock washer, if im not mistaken its a regular split lock washer, which can be obtained at any local hardware store. you should be able to run to a local hardware store, home depot, lowes, etc, and get a lock washer that is of a large enough diameter to slide over the shaft without much play, and install the nut over the top. considering your worn nut situation, you might consider buying a regular washer to place on the shaft before the lock washer to help shim the lock washer out further and increase the number of threads for the nut to grab on, but ideally, it would be wise to replace the nut as well.

while we are on the subject of chains, 90% of the time, chains wear out prematurely because they are not properly maintained. there are alot of different opinions on lubing a chain, however, the guidelines i have always followed, and have worked well for me (which is amazing because i ride my bikes so hard that i stretch chains very quickly), are as follows:

lube the chain once every 400 miles AND everytime it gets wet, bare minimum. some people will say this is too much, however, its certainly not too little and ensures it will always be lubed properly. always make sure to use a good chain lube, and lube it AFTER riding, not before. lubing after riding ensures the chain is warm and allows the lube to seep in better, and it also allows it to cool down and gel up some before your next ride, so that you dont sling as much lube everywhere. My preferred brand of chain lube is silkolene.

also, as stated above, always change both sprockets at the same time, and anytime you change sprockets, change the chain as well.

following the above guidelines, i usually see about 10-15k miles of life out of a 520 chain on a 145 rwhp motorcycle that sees NOTHING but hard riding in the mountains.

another thing you can do to extend the life of your chain if it starts to bind, is clean it, reinstall, and relube. to clean it, remove it from the bike, and soak it overnight in a pan full of kerosene. then let it dry, reinstall, lube it real well, and you should be set. lubing is alot easier if you have a way to prop up the rear tire (ie, center stand or rear stand) because you can set the bike up, crank it, place it in gear, and just spray the chain as the tire rotates.

good luck with it, and be safe, sorry for writing a book.

 

No problem turbo, I appreciate the wealth of knowledge lol

I went to Lowe's and got a washer that fits perfectly and the nut is on there VERY tight now. I rejected this at first because I didn't know what a lockwasher was I had it in my head that it was stationary on one side and moved on the other (for some reason I was thinking the sprocket spun, but not the shaft). I'm so naive sometimes. That's one more thing to add to my knowledge and I'm sure there's a lot more coming!

Thanks for the help guys!

 

a regular lock washer is NOT what you want, look at the part 24 notice the I.D. is splined to fit the shaft, so the washer spins with the shaft then the outside is bent over on a flat of the nut
that regular lock washer might work but at least put some blue lock tite on it then get a real one

 

Polock's right: "GET A REAL ONE" and soon. What you did is better than nothing but it won't hold very long; that's why the "real" lockwasher is splined and tabbed.

 

I just took her for a test ride and it was fine for a minute. Then, the clunking came back. I'm going to pull the cover as soon as it gets cool but I'm thinking the nut spun off again. If not, then it's gotta be the chain.

If you guys remember what it was like to ride a bicycle (multiple speed bike with those thumb mechanisms to shift gear), the clunking feels just like when you went to shift and the chain didn't jump all the way onto the lower sprocket and it clunks at you because the chain is being pushed off the bigger gear but staying on it..... Sorry if that doesn't make sense, that's the best I can describe it...

 

Oh wow. You guys are gonna kill me when you find out what the problem was. THE BACK WHEEL IS CROOKED!!! I can't believe I didn't check that before. I noticed it was wobbly while riding and I went and looked and the right side is way off of the left side. UGH