Manifold oil leak

[vmb]

Seems my IS has sprung a slight oil leak at the base of the manifold on the cylinder head. Its not much but I got this thing about leaks. Just chaned oil (went from 10W40 Amsoil to Rotella synthetic 5W40) and it seems to be a little worse since I changed. Any advise what I can do to stop it. Thanks ahead of time!

[hubcapsc]

Sometimes when the orings on the manifolds go bad, you get a tobacco colored stain around where
they hook to the top end - does that sound like what you're seeing?

If so, changing the orings should fix it...

-Mike

[vmb]

I think u may have nailed it. Sounds like an easy fix. Thanks for your input

[rikb]

Happened to me about 2 months ago.  Changing the o-rings stopped the leaks (had 'em on both banks).  It defineately was oil resting on the heads - fresh, clean oil.   I too, had recentlly changed the oil.  The question is where does it come from?  The air gas mix is coming down from the carbs so no oil there.  Blow back from the cylinders?  Hmm, no smoke in the exhaust, no oil consumption.  No overhead oil leaks dripping down.  Anyone have a theory?

Probably something easy I'm overlooking.

[Gator John]

Mines been doing it in two or three spots for about three years.  Never seems to get any worse.  I just take a little gas on a rag and clean it up maybe 2-3 times a season.

[3W-lonerider]

i seriously dought it's oil your seeing..if you look into any carb you'll see the throttle throat will have a brown tarnish in it.. if you clean it with carb cleaner it will be brown coming out. i think what your seeing is the brown tarnish leaking out past the o-rings and making it look like oil.

[Gator John]

i seriously dought it's oil your seeing..if you look into any carb you'll see the throttle throat will have a brown tarnish in it.. if you clean it with carb cleaner it will be brown coming out. i think what your seeing is the brown tarnish leaking out past the o-rings and making it look like oil.

That makes sense to me.  It has more of a brownish color and not the slipperness that you would expect to find with oil.  I would describe it more like dried tobacco juice. And because the bike has been a little hard starting, I have been putting carb cleaner in the gas a couple times a year, so I am probably encouraging that by dissolving some of the varnish that then bleeds out through the o-rings that are drying out/shrinking since the bike is 13 years old.

Sound like the bottom line is still the same;  the o-rings need to be replaced to correct the problem.  I'm just glad to know it is not a sign of a more serious issue on the horizon.