Keep losing sprocket bolts ??

I recently replaced 3 sprocket bolts that were missing. I use lock tite on all the bolts and went riding this weekend to find out I lost 3 more. In addition to losing the 3 bolts I bent the sprocket.

Why does my sprocket bolts keep coming loose? ;(

Could it be that your rear wheel is not aligned properly.You may be breaking the bolts off from the sprocket pulling on them under power.Just a thought.


Put red loctite on the tapered part of the bolt, not the threads. Make sure your wheel is aligned properly and your chain has at least 2" of freeplay. Later,


I 2nd motomans advice, too much chain tension is a quick way to destroy a hub.

I saw this happen on a brand new 125. Chain wasnt too tight either. I think a bunch of sprocket bolts from yamaha are bad.

Sometimes heat treatments do go the way they're supposed to. I had some hardend valve keepers for my Camaro that were bad from Crane cams. The keepers would pull right through the retainers. Crane sent me a whole new set.

Moral of the story, bad bolts. Change them all out with some after market ones. My bet is the problem ceases.

This has happened to me also. I noticed one bolt was missing and the rest were loose. I tried to tighten them, when one of the bolts BROKE in two. Had to buy another sprocket ($50) and White Bros Talon bolts ($40). I was not a happy camper. Also, noticed my fender bolts were loose with one bolt missing and my kickstarter screw was gone. Since then, I had to RED LOCK TIGHT everything.

Do the Motoman fix, Mine came loose once, I used Blue Loctite and them and all is well I check them after every ride and during....

[ July 24, 2002: Message edited by: E.G.O.**** ]

I have a 1997 RM 125 that we bought used about 6 months ago. We had zero problems with it until we took the sprocket off to put a new one on. We used the same bolts that were there orignally and put the wheel back on. The very next race I landed from a fairly small step up and was taking the turn after it when the whole sprocket just fell off at once. It cracked one piece of my hub right off and the other bolts were missing. Not wanting to buy a whole new hub right away we put on 5 new aftermarket bolts and tightened them all the way down after which putting lock washers and lock tite. After that I checked them after every practice, time I ride, race, whatever. Then one race it came off and broke off another chunk of the hub. And keep in mind I checked them religously for at least 3-4 weeks of riding. I never figured out why it did what it did but we bought new bolts again and tightened them into the 4 remaining slots and I have had zero problems for a month and a half now. It doesn't make sense to me, but I am only 13 years old as well.

I had this same problem on my 1998 YZ400. They came a little loose and the sprocket holes got oblong (spelling??) and I kept loosing bolts. Once I replaced the sprocket and used locktight, the problem went away. I still check them after every ride though! Haven't had a problem on the 2002 YZ426.


My bike was breaking bolts, I know this because one day after a hard ride while loading my bike in my truck my friend noticed a severed bolt still in place, I pulled it out by hand.

I went to my Dad to get me some Good Grade 8 bolts that match size, thread and pitch. His Bolt provider ordered them, I had them the nexted day for Free :) I have never lost one since!!

[ July 25, 2002: Message edited by: YamaFreak ]

My experience is similar to Yamafreak's. If you over tighten the bolts & nuts the bolts will break or start to break. If they are left in place, they will shear into 2 pieces due to the torque that is generated to the rear wheel. If you do not swap out for grade 8 bolts, make sure you torque to Yamaha spec's..

Ny-Lok nuts work very well too.

Thanks fellas!! :)

I bought all new (both) sprockets and chain. I Loctite them all and left 1 3/4" slack in the chain. I will find out tomorrow! :D

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