Topic: Knocking sound

[nickg]

Hi there,
I recently purchased a 1973 cb350f and started it up for the first time in 10 years. All I’ve done is gone through the carbs and changed the fluids. Does anyone know what this sound is? Is it rod knock or poor timing?

Thanks


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[Don R]

 Loose baffle in the exhaust? A stethoscope can help locate the source, or even a long screwdriver held against the suspected noisy area and your ear. 

[newday777]

Hi there,
I recently purchased a 1973 cb350f and started it up for the first time in 10 years. All I’ve done is gone through the carbs and changed the fluids. Does anyone know what this sound is? Is it rod knock or poor timing?

Thanks


Sent from my iPhone using Tapatalk

It sounds like you haven't sync'd the carbs yet and the primary chain is slapping the cases from uneven pressure on the crank.
Sync the carbs in with vacuum guages and that primary chain slap should go away.