Author Topic: Trouble with bike  (Read 22166 times)

Offline Oddjob

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Re: Trouble with bike
« Reply #45 on: March 02, 2025, 08:03:45 PM »
Yes Phil, it sounds like a very loose primary, loading it up with the clutch will make the noise either go away totally or at least lessen it.
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Offline beardylondon

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Re: Trouble with bike
« Reply #46 on: March 02, 2025, 08:18:08 PM »
Thanks again, doesn’t sound like an easy or cheap fix?
1976 CB550 K2 (USA import)

Offline Oddjob

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Re: Trouble with bike
« Reply #47 on: March 02, 2025, 08:20:36 PM »
If it is, then it's an engine out job, about £50 or so for the chain and another £30 odd for the damper rubbers. After that might need a few gaskets, oil and such.
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Offline Sesman

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Re: Trouble with bike
« Reply #48 on: March 03, 2025, 12:11:12 AM »
Might be worth dropping the sump for a visual too? That will seal the deal if loading the drive changes the noise being generated.

Online K2-K6

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Re: Trouble with bike
« Reply #49 on: March 03, 2025, 07:13:08 AM »
I can't see or hear the clip to judge.

But, are you sure it's running on all four cylinder competently  ? If its not, then they sound poor, and that will definitely flick the chains around too.

Basic check is to start it, then stop after 30 sec, to now check the exhaust headers with your thumb looking for a cold one. If any are cool/cold you'd need to look at that cylinder again to get all running well.

Offline beardylondon

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Re: Trouble with bike
« Reply #50 on: March 03, 2025, 07:48:13 AM »
Thanks, click this link and press play

https://www.dropbox.com/scl/fi/c0e7arncvp55ek4sse5av/Honda.m4a?rlkey=8f8y8x3wsnan273dzkov0lhdl&e=1&dl=0

I can't see or hear the clip to judge.

But, are you sure it's running on all four cylinder competently  ? If its not, then they sound poor, and that will definitely flick the chains around too.

Basic check is to start it, then stop after 30 sec, to now check the exhaust headers with your thumb looking for a cold one. If any are cool/cold you'd need to look at that cylinder again to get all running well.
1976 CB550 K2 (USA import)

Offline McCabe-Thiele (Ted)

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Re: Trouble with bike
« Reply #51 on: March 03, 2025, 08:31:10 AM »
That sounds bad, I've been trying to identify if it's a half engine speed sound, Camshaft issues have that marker. I don't know the rotation marker for primary drive noises.

Certainly sounds like the chain is contacting the engine casing.
As Ken had said his test should help identify if it's the primary chain.
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Offline beardylondon

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Re: Trouble with bike
« Reply #52 on: March 03, 2025, 09:42:48 AM »
Thanks Ted and all.

As I say the bike is at my Dads, have passed all this on, and I will report back.
1976 CB550 K2 (USA import)

Online K2-K6

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Re: Trouble with bike
« Reply #53 on: March 03, 2025, 10:11:11 AM »
Thanks, click this link and press play

https://www.dropbox.com/scl/fi/c0e7arncvp55ek4sse5av/Honda.m4a?rlkey=8f8y8x3wsnan273dzkov0lhdl&e=1&dl=0

I can't see or hear the clip to judge.

But, are you sure it's running on all four cylinder competently  ? If its not, then they sound poor, and that will definitely flick the chains around too.

Basic check is to start it, then stop after 30 sec, to now check the exhaust headers with your thumb looking for a cold one. If any are cool/cold you'd need to look at that cylinder again to get all running well.

Yes, tried that but oddly I get a visual representation of it, in bar graph  :) with no obvious option to play. Think I'll need a drum kit along with rhythm (distinctly lacking in my skill set) to replicate the sound  ;D

I've not got the app though, so possibly limited at that point to view properly.

Trying for cold cylinder though, will tell you something.  If it was OK running before, then unlikely to have worn it's chains while inactive.

Offline beardylondon

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Re: Trouble with bike
« Reply #54 on: March 03, 2025, 10:27:16 AM »
This might help...

1976 CB550 K2 (USA import)

Online K2-K6

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Re: Trouble with bike
« Reply #55 on: March 03, 2025, 02:23:33 PM »
For whatever reason I'm not getting that functioning toolbar at base.

Nevertheless, hopefully the tests will turn up something from collect advice so far. Hopefully you'll get a more defined cause and other checks, or solution.

Offline taysidedragon

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Re: Trouble with bike
« Reply #56 on: March 03, 2025, 03:23:16 PM »
That's running rough as a badger's.... Sounds like it's only running on 2 or 3 cylinders to me and something is clattering. Most probably a worn chain.
Gareth

1977 CB400F
1965 T100SS

Offline beardylondon

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Re: Trouble with bike
« Reply #57 on: March 04, 2025, 07:20:25 PM »
Because I’m not overly familiar with this, please could someone post an exploded view showing what they mean by primary drive?

Thanks!
1976 CB550 K2 (USA import)

Offline Bryanj

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Re: Trouble with bike
« Reply #58 on: March 04, 2025, 07:42:52 PM »
Pic from cmsnl off the primary drive hub and primary chain which goes to crankshaft

Offline beardylondon

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Re: Trouble with bike
« Reply #59 on: March 04, 2025, 07:44:02 PM »
Thank you, which number on the drawing is primary?
1976 CB550 K2 (USA import)

 

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