Oil leaking out of header pipe

[TopCatGr58]

Hey Done,

The Valve seals are just rubber, and with the combined heat/and age these engines have seen, they can harden and then leak, but have otherwise no affect on the pistons....except that if they are/were leaking....if it's the intake, then you can get oil fouling of the plugs....if it's the exhaust, just smokey exhaust. Still don't think it's a valve seal though, but as has been suggested, valve cover gasket on inner side leaking down thru head vent hole to the cylinder/exhaust flange/bolt. Just hate to see you go thru all the work to tear into the head to replace valve seals that may or may not be leaking.....however you will also remove the valve cover and then hopefully reseal it with new gasket/sealant...and so will end up fixing the suspected valve cover leak anyways....but may think it was the valve seal that got fixed!? YMMV.

T.C.

[donebysunday]

79sf

Thanks T.C. !
I dropped the filter and emptied it, smelled the oil, seemed good, no gas, oil real clean, reinstalled.
I synced the carbs, still need to set the mix screws. In between cool downs I looked the valve cover over with a 2000 lumen flashlight could not see any wet/shiny surface anywhere, what a clean top end ! Noticed there was much less seepage on the #1 exhaust clamp, still started to smoke but not as much towards the end of my carb sync.
Then I did the rear caliper had been slow to release and started on the front, happened to look up at the head during a breather (still get out of breath too easy) THEN I SAW IT, a small dark burnt oil crusty area between the #1/2 header clamps hidden in the fins. Still can't tell where this is coming from, time for carb cleaner and a small set of assorted brushes to get in there, clean it up and blow some Dr. Scholls foot powder on the area and see.
What say on the mix screws 1.5 turns out to start 79SF ?
Oh pulled the plugs and they are very dark all moist and #1/2 wet.

[TopCatGr58]

Hey Done,

The beginning setting for the pilot screws is ~1.5 turns out from lightly seated. The plugs were dark but you were synching the carbs, so you are only reading the pilot jets. Also, are your jets genuine Mikuni or aftermarket?
What are the sizes of the jets? Are the vacuum slides needles in the middle position? Are the floats at stock or slightly higher?

A photo of the front view of the engine showing the crusty burn oil and such would be good to review.

T.C.

[donebysunday]

T.C.,
Here is a couple shots of the front of the engine, I tried to center the area in the photo, the same for in the spark plug recesses .

[donebysunday]

Was going to pull the carbs but such a nice day.