The work of the black oil spraying gnomes??

[AnnapolisAirhead]

I found an thin, oily, jet black film on the front, of each of the carbs on my bike and I can't find the source.

I completely rebuilt both carbs earlier in the summer and know they were very clean. Mon-Fri I commute about 100 miles each day on the DC beltway and other highways, all paved roads as clean as could be expected. Additionally, I rinse, wax my bike on the weekends. The bike leaves just a tiny (2-3mm) spec of oil from the left valve cover overnight, but otherwise no drips.

The oil was changed about 500 miles ago. Brake (Brembo) calipers rebuilt, new fluid. Fork rebuilt with new seals, fluid, etc about a month ago. Trans and shaft fluid changed 5 weeks ago. Oil pan gasket changed 3 months ago. No drips.

Any ideas? Its all on the exterior of each carb on the front and the part of the carb facing the head and engine block.

Maybe black oil spraying airhead gnomes slipping into my garage at night? I'm puzzled. :scratch

[lkchris]

Brake pad dust.

[DennisDarrow]

Wondering if you have ever worn goggles with a helmet while riding in traffic? Take them off and look closely in the mirror........Rocky Racoon, to say the least.........Better yet, get one of your wife's little make up remover pads and some of her astringent and wipe off your cheeks and forehead.............YUCK.................BLACK CRUD..........

So, imagine what 100 miles per day does to the flat surfaces of the carb bowls, etc............Ride................Dennis

[AnnapolisAirhead]

Brake pad dust.

Interesting. I just rebuilt the calipers and noticed a tiny bit of grinding upon reassembly. That makes complete sense, the air flow would put it there and I even have a little on the final drive at the breather nut.

The brake seem fine now, so I'll wipe and retry.

Thanks Chris, I hate not knowing where things come from or how they happen.

[AnnapolisAirhead]

Wondering if you have ever worn goggles with a helmet while riding in traffic? Take them off and look closely in the mirror........Rocky Racoon, to say the least.........Better yet, get one of your wife's little make up remover pads and some of her astringent and wipe off your cheeks and forehead.............YUCK.................BLACK CRUD..........

So, imagine what 100 miles per day does to the flat surfaces of the carb bowls, etc............Ride................Dennis

Dennis, yeah there's plenty of crud in the air on roads, but this just started and I commute daily. I have a barn sized Cee Bailey that I collect most of my bug art on and a full face helmet for the rest.

I believe Chris nailed it on the head. Its been clean up until I rebuilt the calipers. I'll spray brake cleaner on the carbs and calipers, wipe it up and check them again.

...a wife? What's that? :scratch

[rocketman]

Interesting. I just rebuilt the calipers and noticed a tiny bit of grinding upon reassembly. That makes complete sense, the air flow would put it there and I even have a little on the final drive at the breather nut.

The brake seem fine now, so I'll wipe and retry.

Thanks Chris, I hate not knowing where things come from or how they happen.

Oh, good, let us know what you find out about the chicken-egg problem then would you? :lol

And yeah after years and years and years....as a 40+ mile one way commuter rider myself I know well of the Black Curse. It was really bad when I spent my whole day in city traffic on a bike, you really did look like a racon by the end of the day! (Just Loved getting behind them city buses!)

i would check the underside of the jugs thou esp. in the resess where the cover gasket is. Wipe in there with a folded towel or clean rag. Even with no dripping and new gaskets I'll get an oil flim buildup there. I think becuase the head heats and cools at a diferant rate than the cover. :dunno
RM

[AnnapolisAirhead]

Oh, good, let us know what you find out about the chicken-egg problem then would you? :lol

And yeah after years and years and years....as a 40+ mile one way commuter rider myself I know well of the Black Curse. It was really bad when I spent my whole day in city traffic on a bike, you really did look like a racon by the end of the day! (Just Loved getting behind them city buses!)

i would check the underside of the jugs thou esp. in the resess where the cover gasket is. Wipe in there with a folded towel or clean rag. Even with no dripping and new gaskets I'll get an oil flim buildup there. I think becuase the head heats and cools at a diferant rate than the cover. :dunno
RM
I wipe the bike down thoroughly every weekend. Wash and wax the paint, treat the seat, gently clean the windscreen and wipe the engine down with a rag and a little Kroil. Carbs too, so this was a new thing. My windshield shows the airborn crap we are breathing and riding in though.

Since the bike sat for 8 years, the mufflers and pannier frames were pretty ugly with surface rust--cleaned them up with WD40 and #0000 bronze wool. Now I wash them, wax them and even apply a light coat of Kroil to them too. Then the bike gets wiped down to remove any excess. (yes, I am single, have no offspring, have no life beyond my black lab and my black airhead...:whistle )

...can't solve the chix and eggs deal, but I have been suspicious of eggs most of my life.

[AnnapolisAirhead]

Got home and checked the calipers, same black oily film. Not sure why the pads were grinding at first. Pulled them off and they appear to be fine. :dunno

Anyway, thanks for the suggestions.