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Discussion Starter #1
89 CBR 600 hurricane

I'm having a problem with violent vibration at about 7000 rpm and on. The vibration disappears when I pull in the clutch. I've just replaced the sprockets and chain as well as the rear wheel bearings. I noticed as I spin the rear wheel in neutral with the chain on and tensioned that I hear a ticking noise in the tranny almost like a fishing reel. Is that sound normal? I also noticed that the front sprocket has alot of play. Is that normal? It seems that the mounting bolt doesn't seat against the gear and doesn't hold it tight. Does the vibration sound like a tranny gear? Do you have any other ideas?

thanks

Pierre
 

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Sounds like it could have something to do with the sprokcet and chain change. How Check the slack in the chain, I don't believe the front sprocket, any sprocket should have exessive play like you discribed.
 

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Rotational play or side to side play? Either way it sounds like you got the wrong front sprocket.

Now if the sprocket is rotating the output shaft and there's some play then I can understand that.

But you say the bolt doesn't seem to be tightening down to the sprocket. That sort of sounds like you may have gotten a 520 sprocket instead of a 530 one. 520 and 530 being related to the chain width. How well does the teeth fill the chain from side to side? The 520 being for chain with a 1/4 inch inner spacing and the 530 being for 3/8 inch inner spacing.
 

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I'd lay money on it that you have a newer 600 front sprocket . They just fit over the shaft and then when you drive it , it slips. There's only 2 spline patterns for most the Honda sportbikes. What's the part # on the package or stamped into the sprocket ?
 
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Discussion Starter #5
I put the two front sprockets side by side when I was installing them to make sure they were the same, since I didn't purchase the sets. They were exactly the same width, number of teeth, except the old front sprocket had rubber adhered to both sides. The play in the sprocket is side to side; there is no slipping of the teeth on the shaft.

I took it for a ride around the block yesterday and I noticed the bike is really struggling to get into the higher revs, sluggish, where as before it would be a blink of an eye. The vibration begins when it starts to struggle. Could it possibly be a dead cylinder? I had a car that was only running on 3 of the 4 cylinders and it also showed alot of vibration at high rpms. Any more ideas would be appreciated.

thanks,

Pierre
 

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Take it down a hill and throttle off, pull in the clutch and see if you still have the vibrations. If you don't, then test the compression in each cylinder.
 
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Figured it out!

I took those sprockets off the bike and put them on the lath. I turned them at a slow speed and saw that they were out of round!! Fucking shitty aftermarket crap. Anyways, the sprockets begin to vibrate at about 5 to 7 RPM which seems to be the natural resonance frequency of my gas tank that was missing some rubber bumpers. I put some rubbers on the tank and fab'ed some rubber mounts for the front sprocket like the stock one had and the bike feels perfect now.

Thanks for all your suggestions,

Pierre
 
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