Drive sprocket/bearing noise

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Drive sprocket/bearing noise

Thorby
Sorry I haven't been active for a while, I stopped getting email summaries for some reason so I wandered off from this forum after my long cross-country ride.

Anyhow, the problem: Even though my chain has a good 2 inches of slack my front (drive) sprocket bearing is making a nasty sound and it has friction.  I can tell because if I turn the rear wheel with my hand while the bike is on the center stand, I can feel the friction every 3 turns or so.  Two years ago the chain broke, and got stock in the front sprocket so I bet this put a great strain on it.  The sound makes me very uneasy to ride, I figure at some point the bearing will bind.

Is the front drive bearing serviceable?  Maybe it just needs regreasing?  Or should I replace?

Your wisdom always much appreciated :)
Proud owner of stock '76 CB750.
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Re: Drive sprocket/bearing noise

Thorby


Here's what it looks like.  When the chain broke and got stock in the front two years ago, it started a small oil leak.
Proud owner of stock '76 CB750.
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Re: Drive sprocket/bearing noise

TOOLS1
Administrator
I doubt it took the bearing. You might have a crack though. Clean it up to see if it is, and if it is JB Weld it. Or the seal might be bad. That can be replaced without separating the case. Your snap/binding is more then likely that severely worn out chain, and sprocket binding together. Replace that junk with a new 530 O-ring chain and sprockets.
TOOLS
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1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
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Re: Drive sprocket/bearing noise

Thorby
TOOLS1 wrote
I doubt it took the bearing. You might have a crack though. Clean it up to see if it is, and if it is JB Weld it. Or the seal might be bad. That can be replaced without separating the case. Your snap/binding is more then likely that severely worn out chain, and sprocket binding together. Replace that junk with a new 530 O-ring chain and sprockets.
TOOLS
Thanks TOOLS.  This chain does have a lot of miles on it so I'll start by replacing it.
Proud owner of stock '76 CB750.
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Re: Drive sprocket/bearing noise

seestheday
Be sure to replace both the chain and the sprocket. They wear together.
1981 CB750K with 900 cams
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