leaking oil from exhaust

Just purchased a 1977 kz 650b all original 3500 miles runs great doesn't miss......... Just noticed it was leaking oil from the exhaust and started smoking. Did compression test 95psi to 100psi on all cylinders .... any ideas what my be wrong?

where on the exhaust is the location of the leak? if its by the headpipes, are you sure its not running down from the tach cable? i know that on the 1000's this is a pretty common place to leak oil from, you don't really think about it & it could surely make its ways down by the exhaust flanges and then burn up when it hits them- a leaky valve cover gasket may drip oil down to the exhaust and give this appearance too...

...ditto on madmatt...i too think it is coming from the thin gasket that is right above each exhaust port"valve cover gaskett" these can often accumulate oils from a slow or intermitent seeping and when it gets built up or on a good day ..drips onto or behind the chromed exhuast collers and smokes up a storm...the tach cable also is supect more often than not,it has an o ring and it can become brittle and seep or can be missing all togehter,or have vibrated loose enoguh to seep.. depending on the P.O...i feel any blow by oil would exit through valves as smoke....unless you have oil dripping from the end of the exhuast pipes...in which case..pull the sparkplugs and see if they are wet with oil..if so.....fun times ahead...but dont worry to much..drive it till it stops running and check the oil level often..these old bikes are tough as a honda civic and will run when hurt for a long time....keep an eye on the local c-list for a spare engine or barn bike....90% sure you got some o-ring or gasket weeping though....clean the thing super good with gunk engine bright and a pressured garden hose and you'll maybe be able to moniter it's arrival better...peace...and welcome to kzr

One way to confirm if out exhaust, look at your plugs, oil fouled?

You mentioned smoke... What color?

Positive it is not coming from the seals..... Has after market exhaust 4-1. Could the previous owner have used synthetic oil and that caused the problem and I haven't run the bike long enough to seat seals and rings Bike sat for nearly 30years only has 3500 miles

White smoke took out baffle oil puddled in bottom Pulled the plugs nothing was wet or burnt could it be a possible valve guide

thanks for reply. just found problem.oil on # 3 cyl plug.i don't know what to do know.excessive oil leaking out of header after warmed up. i mean pouring out.could it be top end at chance?do i replace rings top end or what? need help

Wait one for a moment... If plug number 3 not oil fouled then based on being number 3 cylinder, confirm it's not the tach seal that's leaking.... It sits right above slightly to the right of exhaust port # 3....

OMR

thank old man rock. but im sure its not tack seal.i let the bike run for one hour to let oil left in pipe burn of only to see it pouring out the pipe were it boults to header were the pipes meet the baffel.so then i shut it down puled plugs again to find #3 plug was wet.im going to try changing oil to 10 40 not sure what preveas owner had in but was clean .the only reason i say its not a seal or o ring is that the motor is so clean i could eat off it.also the oil level was at center of bubble

compression and leak down test would provide you some insight as to possibilities...

Due to "Oil pouring out" Piston oil ring, exhaust valve stuck open, valve oil seal etc... Unfortunate as it may be, you'll have to go through the process before tearing her apart....

Bummer....

Bummer....
bj1lake thank old man rock. but im sure its not tack seal.i let the bike run for one hour to let oil left in pipe burn of only to see it pouring out the pipe were it boults to header were the pipes meet the baffel.so then i shut it down puled plugs again to find #3 plug was wet.im going to try changing oil to 10 40 not sure what preveas owner had in but was clean .the only reason i say its not a seal or o ring is that the motor is so clean i could eat off it.also the oil level was at center of bubble

well... that sounds like an internal oil leak to me. either rings, or valve seals. It is most likely valve seals. The motor can only have 3500 miles on it and look clean as a son of a bitch from the outside. But the rubber valve seals inside harden up over time and will most definetly cause this problem.

the oil that seeps past the valve seals gets into the exhaust or intake ports and works it way through either the cylinder if its an intake valve seal leaking (causing smoke) or past the exhaust valve and into the exhaust port also causing smoke and oil leakage.

the oil will gather at the lowest spot of your exhaust system and work its way out.

Just some comments that might help.
After being stored for 30 years,,,
Some seals and gaskets are just dried out and NO GOOD anymore unless someone was starting it up once and awhile.
Probably at least a few springs are NG.
A spring sitting in compression for 30 years will do it no good.

To find a leak, look for the CLEANEST spot on the engine.
Oil is a great solvent.
If that doesn't help you find it.
Go to the drug store and ask one of the nice ladies for a can of ladies SPRAY deodorant with the baby powder in it, do a light spray on the engine and you will find your leak source.