Author Topic: Top end noise cb500  (Read 933 times)

0 Members and 1 Guest are viewing this topic.

Offline hudstr

  • Full Member
  • *
  • Posts: 62
Top end noise cb500
« on: August 16, 2018, 07:35:13 PM »
2 different cameras so hopefully one of them picked it up well enough to hear it.

I had always just assumed this was cam chain noise but after loosening the adjuster while the bike was running, It produced a different more slapping like sound, whereas the noise is more of a constant whineing. It may be hard to hear because the carbs arent synced very well so the clutch makes noise and there is a few holes in the exhaust. The sound is present is there at idle and on throttle, and it gets louder with throttle. It sounds like it is on both sides on the top end.

What could this sound be, cam journals, the tappet thingys which I cant remember the proper name of right now?
When a passenger of the foot hove in sight, tootle the horn trumpet
to him melodiously at first. If he still obstacles your passage
tootle him with vigor and express the word of mouth the warning "Hi! Hi!"

Offline BRG-BIRD

  • Enthusiast
  • **
  • Posts: 158
Re: Top end noise cb500
« Reply #1 on: August 16, 2018, 08:24:30 PM »
Have you checked the rocker shafts to see if they are wearing into the rocker cover?
“You are either on something or onto something.” The Comman Man

Offline RAFster122s

  • I feel like a really really
  • Really Old Timer ...
  • *******
  • Posts: 12,534
  • SOHC4 member # 2605
Re: Top end noise cb500
« Reply #2 on: August 16, 2018, 10:45:11 PM »
I believe the 500 used pinned rocker shafts and does not suffer that issue like the 550s from 74-76.
David- back in the desert SW!

Offline Deltarider

  • Really Old Timer ...
  • *******
  • Posts: 8,174
  • ... but some animals are more equal than others.
Re: Top end noise cb500
« Reply #3 on: August 16, 2018, 11:34:56 PM »
I believe the 500 used pinned rocker shafts and does not suffer that issue like the 550s from 74-76.
Depends on your enginenumber. Consult the Parts Lists at Honda4Fun: http://www.honda4fun.com/materiale-documentazione-tecnica/parts-list/parts-list-cb500 I did not read where you're located. As I understand it from # 2006337 you're good for US CB500 models and from #2170315 for the CB500K2 (ED, F, G) a model that was marketed around 1976 in Europe.
Generally it is not recommended to adjust the camchain adjuster whilst running. Clymer and the Honda CB500K3/CB550K3/4 Owner's Manuals give bad advice here. See FAQ.
« Last Edit: August 17, 2018, 12:00:11 AM by Deltarider »
CB500K2-ED Excel black
"There is enough for everyone's need but not enough for anybody's greed."

Offline dave500

  • Really Old Timer ...
  • *******
  • Posts: 17,052
  • WHAT?no gravy?
Re: Top end noise cb500
« Reply #4 on: August 17, 2018, 12:40:31 AM »
only the later 550s had those pinned rocker shafts,no 500s did nor the early 550s.

Offline dave500

  • Really Old Timer ...
  • *******
  • Posts: 17,052
  • WHAT?no gravy?
Re: Top end noise cb500
« Reply #5 on: August 17, 2018, 02:30:25 AM »
first things first!square away the ignition settings first!out of sync carbs will make any motor sound crap,syncing them over #$%*ty ignition isn't the done thing,go over your ignition first and get it all spot on first,#$%* around with carbies last,dont say "thingys"its girl speak!

Offline hudstr

  • Full Member
  • *
  • Posts: 62
Re: Top end noise cb500
« Reply #6 on: August 17, 2018, 05:53:39 PM »
Timing was set with a timing light <200 miles ago. Valves were done <200 miles ago and I checked them again before I tore into it. engine number 2015916 USA k1 so I think this means I don't have to worry about rocker shafts wearing right?

I know adjusting the chain while running isn't recommended, I was just trying every available option, like putting pressure on the kickstarter while adjusting to pre-tension. When I loosened it while running, it made a pretty loud rhythmic slapping sound. The sound I am concerned about is a constant sound, not like tappets but something constantly rubbing or touching. It is present at idle and on throttle, and gets louder with more revs.

Here's pictures of the rockers and cam, I didn't see anything too bad, other than that someone has been in here before with sealant, but at least they didn't dump a whole tube on it. So now it seems I back to square one.





When a passenger of the foot hove in sight, tootle the horn trumpet
to him melodiously at first. If he still obstacles your passage
tootle him with vigor and express the word of mouth the warning "Hi! Hi!"

Offline hudstr

  • Full Member
  • *
  • Posts: 62
Re: Top end noise cb500
« Reply #7 on: August 17, 2018, 06:44:35 PM »
I've been trying to find videos of running bikes to compare sounds but its a bit difficult because everyone just wants to show off their new exhaust.  ;D  I did find this video but its still kinda difficult to differentiate the sounds. Is the constant chssssssssssss sound just something that these bikes do?

When a passenger of the foot hove in sight, tootle the horn trumpet
to him melodiously at first. If he still obstacles your passage
tootle him with vigor and express the word of mouth the warning "Hi! Hi!"

Offline scunny

  • Old Timer
  • ******
  • Posts: 4,615
  • don't call me expert
Re: Top end noise cb500
« Reply #8 on: August 17, 2018, 07:01:49 PM »
The tappets sound like rustling leaves.
past-cb100,ts250,cb500,cb500,gs1000,gs650g.phillips traveller
present-CB 650 retro
            VTR1000F3
           XL250S riverbed rocket
           TS250[sold]
           TS185[sold]
           XL125S[sold]
           MT50 (white)
           MT50 (red)[sold]
           KN250/XS400 project
           XR/XL250 bitsa under construction
           SL100[sold]
           XL250R
           pedal(pub bike) leaks oil
my gallery http://gallery.sohc4.net/members/personal/scunny

Offline dave500

  • Really Old Timer ...
  • *******
  • Posts: 17,052
  • WHAT?no gravy?
Re: Top end noise cb500
« Reply #9 on: August 18, 2018, 02:53:11 AM »
these aint exactly a silent motor although in the day compared to out dated for the time English rubbish they were.

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,802
Re: Top end noise cb500
« Reply #10 on: August 18, 2018, 09:46:40 AM »
Do bear in mind the cam chain rides on a shoe during operation.  Even though it is a polymer shoe, it's not noiseless.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline hudstr

  • Full Member
  • *
  • Posts: 62
Re: Top end noise cb500
« Reply #11 on: August 18, 2018, 05:31:39 PM »
I bought a top end gasket kit for the rocker cover gasket and the little o-rings on the ends of the rocker shafts so I'll get started on that when it gets here. Also I noticed the tappets have flat spots on them so on Monday I'm going to see if any nearby places can regrind them for cheaper than $48 which is what a new set would cost. I've seen services advertised on ebay for tappet grinding but they were like $40 not including shipping plus waiting several days to get there, a couple days turn around and several more days back.
When a passenger of the foot hove in sight, tootle the horn trumpet
to him melodiously at first. If he still obstacles your passage
tootle him with vigor and express the word of mouth the warning "Hi! Hi!"

Offline RAFster122s

  • I feel like a really really
  • Really Old Timer ...
  • *******
  • Posts: 12,534
  • SOHC4 member # 2605
Re: Top end noise cb500
« Reply #12 on: August 18, 2018, 07:58:25 PM »
Hudstr, check prices on new tappet adjuster screws at South Sound Honda in Washington state, some of the cheapest prices and reasonable shipping charges as well!
Just looked it up, $3.88 each, retail $5.17
Add a few other things you need and shipping cost is spread over more parts.

David
David- back in the desert SW!

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,802
Re: Top end noise cb500
« Reply #13 on: August 19, 2018, 12:24:00 AM »
Aren't the tappet faces hard chromed?
Grinding them would just remove what remains and lead to accelerated wear of both tappets and cam.
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.