Rubber oil debris... a cause for alarm?

Today I decided to take care of a really annoying oil leak that's been pissing me off for a while. (Clutch pushrod seal) I pulled off the transmission cover and found this debris in the oil that was pooled up in the bottom of the cover. It seems to be a very hard rubber or plastic. I am assuming this is probably bits of the cam chain guide or roller? I know this motor was fully rebuilt top to bottom about 10,000 miles ago, but I have no idea on the condition of these parts. I am running a manual tensioner, and have set it with the typical procedure of tightening until contact and backing off a quarter turn or so. (So I'm ruling out that being too tight.) Is this a pretty normal occurrence, or should I be considering pulling the head off for a closer look? I really don't need the added work right now...

I don't know if that is cause for alarm or not, but if mine I would not start by pulling the head. I would pull the oil pan and see if there's a bunch of debris in there. Ed

Could be the cam chain guide or might be some black RTV residue if the person used sealer when he rebuilt the engine.

They did use black RTV on the case halves, but this stuff is very hard, like the chain guide material, or the way the rubber rollers get when they are OLD. It's been 10,000 miles and 15 years since the engine was rebuilt, and I don't even know if the cam chain components were replaced at that time. I'm worried about one of those pieces letting go and causing an ugly situation...

I'm not familiar with your bikes engine? BUT

I had a similar thing happen to me. During my 1000 engine rebuild, I replaced all the cam gear...... idlers and rubbers.

I noticed the black material in my oil change. It was from the cam chain finding its way around the new items. The cam chain wore or chewed the plastic on the side of the idler gears.

The other thing that can happen is that the cam gear or idlers are worn out and wobbling around causing the cam chain to chew up things. If the cam chain is really loose on a 1000, it can chew up the front cylinder slider......causing bits of black plastic in the oil.

good luck

I dropped the oil pan today after work. OH SHIT. This looks bad.

A lot of rubber.

I have tomorrow off of work. A good stormy night to stay up late and work on the bike. I figured that something in the cam chain tensioner system is coming apart due to old age. There wasn't any debris in the oil the last couple times I changed it... I pulled the cylinder head and found this. Looks like we have the suspect.

...This sucks. I really didn't want / need another project right now. I AM glad that I caught this before it totally came apart and something worse happened.

Good Save! It's time for some Liska parts!

That was lucky that you caught it. Change everything while you are in there including the rubber spacers. There are two different sizes so make sure you install the spacers in the right place.

Trying to get a better grasp of this stuff....the part that's all chewed up should be shaped to keep the chain from moving side to side? Does the chain go between the two wheels you're holding? It pivots when pushed on by the tensioner to hold tension on the chain?

So in the first photo it would pivot where your thumb is? The tensioner shaft would come in from the right side and push on that slightly domed area? The chewed up wheel actually applies the tension to the chain? Or do I have it backwards?