Black plastic bits in sump filter screen

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Changed the oil tonight on my 73 850, and in cleaning the sump "filter" screen I found some small bits of black plastic inside. Nothing else seems amiss, but just wondering where they could have come from (and if they're an early warning of something I should take note of).
 
Rotted oil line. The inner and out of the line are different compounds. outside may seem fine but inside brittle.
First guess.
 
pvisseriii said:
Rotted oil line. The inner and out of the line are different compounds. outside may seem fine but inside brittle.
First guess.

A good one, nevertheless...
 
I don't think it's the oil lines, as all of them are new within the last couple years (still possible, yes...) - but a good guess nonetheless.

Could be valve guide seals or timing chain "slipper," I suppose. I'll monitor for now. Planning on going in the timing chest this winter anyway, so I'll find out then about the chain I guess.

Thanks for the advice, folks.
 
If there are some bits in the sump, there are other bits floating adrift that could find thier way into an oil passage at a critical point such as a rod bearing, potentially resulting in disaster.

Riding and waiting till winter to set it right isn't the best course of action...
 
Thanks Paul. Found nothing else in the oil or the filter, so I'm surprised and confused, but optimistic...
 
I agree with bwolfie, the plastic on the cam chain tensioners is notorious for coming adrift. I would be checking it before I rode very much. The steel behind the plastic is not hardened and the chain will chew it up rapidly. Jim
 
Are there certain years/models that have the plastic lined cam chain tensioners?

Looking at Old Britts oil flow chart, it does look like the sump screen would be the first logical "catch point" for debris from the timing chest, but I can't quite be sure.

Oil, oil filter, and the screen in the tank were debris-free. Just those little bits in the sump plug screen. Baffling.

ANYBODY GOT A PICTURE of a plastic lined tensioner? Sure would be useful to see if the plastic looks like what I found.

Thanks
 
BrianK said:
Are there certain years/models that have the plastic lined cam chain tensioners?

Looking at Old Britts oil flow chart, it does look like the sump screen would be the first logical "catch point" for debris from the timing chest, but I can't quite be sure.

Oil, oil filter, and the screen in the tank were debris-free. Just those little bits in the sump plug screen. Baffling.

ANYBODY GOT A PICTURE of a plastic lined tensioner? Sure would be useful to see if the plastic looks like what I found.

Thanks

Courtesy of RGM/
Black plastic bits in sump filter screen
 
Thanks pvisseriii!

Can't really tell yet. My bits look "blacker" and more plastic-y, less rubber-y, but who knows. Guess there's a timing chest incursion in my future....
 
BrianK said:
Thanks pisseriii!

Can't really tell yet. My bits look "blacker" and more plastic-y, less rubber-y, but who knows. Guess there's a timing chest incursion in my future....

I wouldn't reference color. Into the timing side for you.
 
Now let's not go crazy here. We're talking about a few plastic bit? Not metal, not bits of piston or rings. How much of this stuff is evident? How big are the bits?

My real concern would be the cam chain tension. If this hasn't been check lately then I guess now would be a good time, along with looking into the oil way behind the oil pump, otherwise run some less expensive oil through the system a couple times and enjoy the miles while you're at it.

If, however, you have an abundance of this material surfacing, which i doubt you will, then identifying it may be necessary.

Change some lines, flush the system a few time and check timing chain as a precaution but don't lose a whole lot of sleep over this.
 
could it be possible the oil pump nipple decayed and its pieces got flushed out of TS area. Are you sure its rubber?
 
Cam Chain side plates wear a grove in the insulator , produceing grotty gnarly little bits and swirls daggs or gnashings
till the rollers are in contact.perhaps .

So the timing chain is a service adjustment. Could pre groove the tensioner . Nothing but fun . Got a chopped cover.
Dont lean on things adjusting , without the spindle locator device fitted. Not that that isnt impossible .

The idea is to refit the cover with three or four bolts , if swinging the engine over , to check in three places .
High quality chains shouldnt stretch.Maybe . :twisted:

The Renolds Raceing chain was higher strentgh than the standard , so H.D. useage woulnt break it . :) It'd Just Stretch .

8) :lol: :P :oops: :shock: :?
 
There wasn't much of it, and most was very small bits, almost like "large grains of sand." There was one somewhat larger piece, which was more like a little sliver. Color was a bright, plastic-y black. The "sliver" looked and felt like a small piece of vinyl, and was maybe 3/6" inch long, 1/32 or 1/16" inch wide, and paper thin. As I mentioned, all of this looked more like plastic than rubber.

Appreciate all the help!
 
The smaller the stuff, the easier it can get into rod bearings and cause problems.
 
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