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Author Topic: Engine noise  (Read 1286 times)

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Offline Eddiev

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Engine noise
« on: March 11, 2019, 07:52:37 PM »
Just bought this bike and I'm working on getting it running well. It's a 82 cb650 if it matters.  I noticed this noise come up after it warms up. Is this something I should be worried about?


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Offline 05c50

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Re: Engine noise
« Reply #1 on: March 12, 2019, 05:50:43 AM »
I always have a hard time distinquishing noises from posted videos, but there are two common noises in these bikes that sound similar. One is caused by the carbs not being properly syncronized and the other is clutch rattle. The clutch rattle will change when you pull the clutch lever in and the sync noise will change if you raise the idle slowly.

..........Paul
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Wear a helmet,the life you save may be your own.Ask me how I know.               CB650C,CB550F,GL1000,CB750A

Offline Eddiev

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Re: Engine noise
« Reply #2 on: March 12, 2019, 03:29:19 PM »
Thanks for the reply! What I'm hearing does sound like it very may well be clutch rattle. It does sound like the noise is considerably louder on the left side of the engine where the shifter is. I just got the carbs to do OK at idle, so I know the next step would be getting them sync'd. This probably won't fix the noise because it does sound mechanical so I'll take a look around the forums for info on the clutch rattle.

Any advice on what post has the most info on how to fix? or may this be something I'll just have to deal with?

Again, thank you so much for the help!
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Offline 05c50

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Re: Engine noise
« Reply #3 on: March 12, 2019, 03:42:09 PM »
Don't discount the amount of noise that can be caused by carbs that aren't synced properly. You can get some pretty loud clunking and knocking that will go away once all four cylinders are firing evenly. Even some clutch rattle will quiet down when the engine is running properly.

......Paul
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Wear a helmet,the life you save may be your own.Ask me how I know.               CB650C,CB550F,GL1000,CB750A

Offline CB650CPastor

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Re: Engine noise
« Reply #4 on: March 17, 2019, 07:02:34 PM »
I agree. That is definitely clutch rattle. I'm a recording engineer and I know sounds! Carb sync will minimize it, but you may never eliminate it.
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Tim
Current:1980 Honda CB650C Custom, 1969 Toyota Corona Deluxe Sedan
Past: '07 Honda Rebel 250, '80 Yamaha XS1100 Special, '69 Honda CB160, '67 K15 Suzuki Hillbilly, 1971 VW Super Beetle...

Offline evinrude7

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Re: Engine noise
« Reply #5 on: March 17, 2019, 07:09:02 PM »
Quote from: CB650CPastor on March 17, 2019, 07:02:34 PM
I agree. That is definitely clutch rattle. I'm a recording engineer and I know sounds! Carb sync will minimize it, but you may never eliminate it.

+1
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Offline lafindufondu

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Re: Engine noise
« Reply #6 on: March 18, 2019, 05:40:09 AM »
I've heard thicker clutch spring washers could help the clutch rattle.
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Offline bryanj

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Re: Engine noise
« Reply #7 on: March 18, 2019, 05:44:43 AM »
Dont see how as there are no spring washers on the clutch. If you mean the washers under the bolts holding the plate with springs again wont alter anything as the bolts are tightened down fully not left with play like on old brit bikes
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Offline lafindufondu

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Re: Engine noise
« Reply #8 on: March 18, 2019, 06:15:53 AM »
You're right, I'm wrong  Can't find that thicker washer info anywhere  ::)
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Offline uksparky

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Re: Engine noise
« Reply #9 on: March 18, 2019, 07:58:31 AM »
Check the clutch basket if its like the 550s it has rivets they come loose causing clatter
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