Topic: Metal in my oil: Should I be worried?

[jtb]

Another thread hijack,  Gordon, I've been thinking about trying to get a group like the Rusted Nuts going in Birmingham.  Does your name refer to rusted nuts on the bikes or the owners?
 
John

[jotor]

Also, it's bolt stretch, not fastener binding that keeps things together.

But what if the the fastener binds prematurely and the bolt has not stretched as far as it should?    Just tossing that out as a puzzler. 

Which is why you put the "thick stuff" on--so it won't bind.

IMHO, as always.

Joe

[VitaminCB550]

THough I try not to do things if I don't have to, I must ask one question: How was it running before you did this oil change? 

[Raul CB750K1]

This is what I found when I dissassembled my CB350 engine (thanks God for digital cameras?


Raul


P.S. Hod did people restore old bikes before digital cameras? Man, I guess I have two thousand pictures and I'm still halfway through it!!!

[Raul CB750K1]

A couple more...

[Bob Wessner]

How did did people restore old bikes before digital cameras?

I agree and I would add the Internet. 

[sparty]

THough I try not to do things if I don't have to, I must ask one question: How was it running before you did this oil change? 

It seemed to be running fine for a 34 year old bike, but what do I know, it is my first sohc4.  
I used the magnet technique last night and it appears that all of the metal is aluminum.  I am not sure if that is good or bad news.  
I was reading my Clymer last night and I plan on adjusting the valve clearances and camchain according to its instructions.  I will also be inspecting the oil pump and changing its screen.

[Bob Wessner]

Don't wish to exacerbate your level of anxiety, but that's a bunch of "stuff" in my opinion. Better find out where it's from. Good luck and let us know.

[sparty]

A couple more...

Raul, 
Wow, there was a ton more metal in your machine than I have found in mine.  What did you say your diagnosis was again?

Bob,

I certainly intend on finding the problem, I hop that it is the camchain rubbing the head and nothing more serious.  If you have any suggestions, I'd like your input.  Thanks.

[Bob Wessner]

Bob,

I certainly intend on finding the problem, I hop that it is the camchain rubbing the head and nothing more serious.  If you have any suggestions, I'd like your input.  Thanks.

I've not faced the problem yet <knock on wood> so your best bet would be the suggestions of more experienced folks here. Wish I had a good suggestion as to source and cure though.

[Gordon]

If it's all just aluminum, there's a good chance it's just the camchain rubbing the head and cylinder block.  Like others have said, it's possible this could merely be due to lack of previous adjustment, so try that method first and see what happens. 

When adjusting the camchain, take note of what the engine sounds like before you do anything, and then what it sounds like after.  There's a very distinct sound the chain makes when it's loose, especially when it's rubbing against metal.  Sounds sort of like a fast-moving chain rubbing against metal.

If that is the problem, you will know almost immediately because the top end will suddenly get much quieter.   

[Raul CB750K1]

A couple more...

Raul, 
Wow, there was a ton more metal in your machine than I have found in mine.  What did you say your diagnosis was again?

Bob,

I certainly intend on finding the problem, I hop that it is the camchain rubbing the head and nothing more serious.  If you have any suggestions, I'd like your input.  Thanks.

The diagnosis was clear: the cylinder tunnel walls where the camchain runs through were grooved: loose cam chain. Also, when dismantling the tensioner, it just popped. Apart from some other blunders I found on the engine -been rebuilt before by some unskilled frenchmen (can say that now that I know there are no french around HAHA)-, I believe the rebuilder forgot to release the plunger once the engine was rebuilt. The camshaft lays on aluminium bushings, but the amount found is far bigger than what it can wear from the bushings before the engine destructs itself.

Raul

[jotor]

Apart from some other blunders I found on the engine -been rebuilt before by some unskilled frenchmen (can say that now that I know there are no french around HAHA)

Raul

J'en suis sûr!

[Boomologist]

Hi,
What did the inside of your oil filter housing look like? Was the filter "heavy"? Can you look into the outlet  passage from the filter and see any metal?
If enough metal/crud got in the filter and plugged it the valve in the filter housing bolt will open and bypass the filter. This will put anything that would be trapped by the filter directly into the oil system. When this happens it usually plugs the oil to the cam. Be sure to flush out the oil passages.

On the topic of anti-seize, if I have replaced my bolts with allen head type, which are much harder than oem and won't "stretch" like oem, will that change the torque spec's?

[bryanj]

OK here goes, All these bikes were current when i was a "professional" wrench
Fours-- Relatively common to fin aluminium "dust" congealed into a lump in the filter casing. usually from slack camchain and too long between oil changes, not always a disaster but if you strip down do remember to be VERY critical about the cam chain tensioner rollers--they are old rubber that has been hot cold hot lots of times

Twins--because you have to do extra work ( and it ain't spec'd till way out of warranty) the centrifugal filter on the crank end rarely gets cleaned which can starve the top end as its only a plunger pump, plus oil pump screen (clean at same time) picks up all the rubber and gasket crap and blocks also starving the top end.

If only people would actually READ the service schedule and notice that there are maximum TIMES as well as Mileage between services most of the Lube problems experienced would never happen.

Honda spec 10w40 instead of 20w50 cos its thin enough when cold to get through all the tiny restrictors and not let the top ends starve of oil, 20w50 might be better for and "old and abused" bottom end but those restrictors will probably have got smaller due to crud deposits not bigger.

[Raul CB750K1]

Have a look at this picture. It's the tensioner of my CB350 twin. I guess it goes without saying which is the new one...

The jockey wheel below is independent, while the wheel above forms a unit with the metal bracket. When I dismantled the engine I ordered both parts as a matter of fact. After all, they are just rubber wheels, and though the upper one seemed untouched I ordered it. I regret now, it costed 45 euros. Ouch!!

The jockey wheel was about 10 euros, much more affordable. The tensioner plunger presses on the metal bracket on the above wheel. The fact that it's untouched and the wheel below badly worn reassures my theory that the tension was not adjusted and the camchain was loose, therefore scraping the cylinder walls.


Raul

[superchode]

wow, Raul. our engines are mirroring each other.  my lower cam chain roller looked almost exactly like that - less than 1/2 it's normal size. my cam chain slide was worn beyond belief as well - and there was all kinds of engine block sitting down in my oil sump (in shavings form).  the cam chain adjuster seems to function just fine - it just wasn't used... with predictable results.

hopefully my engine appreciates me rescuing it from its previous, abusive owner.

[Raul CB750K1]

hopefully my engine appreciates me rescuing it from its previous, abusive owner.

Yeah, I sometimes use that as consolation, but tell you what, rescuing abused bikes is outrageously expensive!!!!


Raul

[superchode]

please refrain from reminding me of that in the future.