Honda-SOHC

SOHC.co.uk Forums => CB500/550 => Topic started by: badger_eng on November 05, 2026, 06:28:31 PM

Title: Any ideas?? Have you seen this part?
Post by: badger_eng on November 05, 2026, 06:28:31 PM: Started to clean the crankcases halves, barrels, head etc today prior to vapour blasting.

Dropped the sump pan into a washing bowl with a cup full of petrol in, started degreasing it and as I worked my way through the sludge caked into the ribs in the bottom of the sump, I could hear a metallic noise as I brushed away in the petrol / oil mix???

The metallic sound turned out to be this….

[attachimg=1]

Does anyone have any idea what it is??

Thanks in advance

Pete
Title: Re: Any ideas?? Have you seen this part?
Post by: Athame57 on November 05, 2026, 07:00:19 PM: Hi
I'm no CB550 man myself, but a hunch had me explore the diagram here on the cmsl site. Looking at the shape could it have anything to with this? (arrowed)
Title: Re: Any ideas?? Have you seen this part?
Post by: badger_eng on November 05, 2026, 07:09:35 PM: Thanks for the reply…. I’ve been doing the same. Looking through the exploded diagrams and parts lists for all the internal (to the engine) items.

The item you highlight is the cam chain adjuster and tbh, when I removed the assembly it looked like all parts were present. However, this is also my first CB550 strip so although the cam chain assembly looked complete and is now bagged up and stored, I’ll revisit it tomorrow and see if it could be part of it.

After buying the bike, I’ve only ran it in the garage to work through the PO’s long standing carb problems and then again to fit another set that Ian supplied me with.
I have done no maintenance, just straight into the stripdown process so if it is from that area, it could have been there for a long time.

I can see no shear or fatigue points on the offending item so it could be a loose item from that area…. or not 🤔

Like I said, I’ll take a look at the cam tensioner assy tomorrow and see if it could be a stray part.

Thanks again 👍
Title: Re: Any ideas?? Have you seen this part?
Post by: Nurse Julie on November 05, 2026, 07:24:51 PM: Belongs on the cam chain tensioner as pointed out by George
Title: Re: Any ideas?? Have you seen this part?
Post by: Athame57 on November 05, 2026, 07:31:06 PM: Quote from: badger_eng on November 05, 2026, 07:09:35 PM
Like I said, I’ll take a look at the cam tensioner assy tomorrow and see if it could be a stray part.

Thanks again 👍

This looks more convincing! ;)
Title: Re: Any ideas?? Have you seen this part?
Post by: badger_eng on November 05, 2026, 07:47:58 PM: Quote from: badger_eng on November 05, 2026, 07:45:58 PM
Forget Nurse Julie....

Instant promotion to Sister!!

I wonder how long its been laid in that sludge :-)

Thanks Julie / George, much appreciated.

Pete
Title: Re: Any ideas?? Have you seen this part?
Post by: Bryanj on November 05, 2026, 08:07:42 PM: May not be from the tensioner you have but from a previous broken one, that sort of thing happens when the screwdriver slot is used to tension the chain
Title: Re: Any ideas?? Have you seen this part?
Post by: badger_eng on November 05, 2026, 09:19:29 PM: Good point. It may be that I have a spare now :-)
Title: Re: Any ideas?? Have you seen this part?
Post by: Bryanj on November 06, 2026, 04:04:47 AM: Except if that falls out the tensioner is broken
Title: Re: Any ideas?? Have you seen this part?
Post by: badger_eng on November 06, 2026, 07:50:52 AM: I shall feedback what I find later today….