Author Topic: 4th Cylinder tapping noise and visible exhaust  (Read 351 times)

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Offline Happy Elbow

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4th Cylinder tapping noise and visible exhaust
« on: August 04, 2014, 09:41:28 AM »
Hey guys, at the end f my ride today I started to hear a tapping noise from the fourth cylinder, and there was visible exhaust coming from the 4th cylinder exhaust pipe (its a 4 into 4). I'm thinking it has something to do with the valves, as that would explain the ticking. Can anyone advise? Thanks.
1978 CB550K

Offline flybox1

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Re: 4th Cylinder tapping noise and visible exhaust
« Reply #1 on: August 04, 2014, 10:06:51 AM »
did you pull off the #4 tappet covers and take a look? what did you see?  what is the current valve gap setting?  is the lock nut tight?
when was the last time you completed all the 3000mi maintenance items?
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mineā€¦"

Offline Happy Elbow

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Re: 4th Cylinder tapping noise and visible exhaust
« Reply #2 on: August 04, 2014, 10:51:15 AM »
the tappet adjustment screw nut on the intake seems to have been a little loose. I readjusted to 0.02" and the problem seems to have been adressed. We will see if the problem returns after a decent ride later.
1978 CB550K