Author Topic: CB550f tapping noise  (Read 699 times)

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Offline peteuk

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CB550f tapping noise
« on: September 13, 2016, 06:53:09 am »
Hi,
I own a 1977 Honda cb550f. It has developed a tap tap tapping noise that sounds like it's coming from number 1 cylinder exhaust tappet. I have removed the cover and there is no obvious damage the cover. The strange thing is tho that if I disconnect number 1 spark plug the noise stops. As soon as I reconnect the plug cover, the noise returns. Any ideas would be greatly appreciated. Thanks......Pete

Offline calj737

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Re: CB550f tapping noise
« Reply #1 on: September 14, 2016, 05:16:54 am »
Certainly check that the valves are properly adjusted on that cylinder. Remove and reinstall the spark plug, ensuring its properly seated. And lastly, it may need a new exhaust gasket. These are one-use crush copper O-rings. If the exhaust has been removed, then re-installed without replacement, its very possible that you've developed a leak and are not sealing the port.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

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Offline Stev-o

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Re: CB550f tapping noise
« Reply #2 on: September 14, 2016, 06:50:26 am »
+1 on Cal's suggestions and then do a vacuum sync on the carbs.
'74 "Big Bang" Honda 750K [836].....'71 Honda 750K project.....'76 Honda 550F.....K3 Park Racer.....K5 Fiddy Dolla Special!......CB500 Fiddy Dolla Special too!!............plus plus plus.........

Offline Bob a

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Re: CB550f tapping noise
« Reply #3 on: February 02, 2020, 12:06:59 am »
Swap the spark plug over with another cylinder and see if the cylinder that now has that plug makes the noise and it has gone from the original.
If that works I would renew the plugs.

Offline Stev-o

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Re: CB550f tapping noise
« Reply #4 on: February 13, 2020, 01:59:24 pm »
Swap the spark plug over....

Hoping he has it repaired by now as it's been over 3 years!
'74 "Big Bang" Honda 750K [836].....'71 Honda 750K project.....'76 Honda 550F.....K3 Park Racer.....K5 Fiddy Dolla Special!......CB500 Fiddy Dolla Special too!!............plus plus plus.........

Offline Nurse Julie

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Re: CB550f tapping noise
« Reply #5 on: March 05, 2020, 02:21:46 pm »
Swap the spark plug over....

Hoping he has it repaired by now as it's been over 3 years!
Yes, he had it all sorted within a few hours, it was a blowing exhaust header. He is in UK and on our SOHC forum, as soon as we saw the video, the problem was diagnosed instantly.
Trust me I'm a Nurse, I promise it won't hurt....much

 

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