huge amount of smoke...

hi all,
looking for some advice. have a kz650 1979 and for a while now its been running rough but fine once warm.
if i leave it over night, when i start up its very hard to start and when it does it only runs on 2/3 cylinders.
with huge amounts of thick smoke that smells like oil. its so bad i actually had a neighbor come out and ask me to turn it off.....

when i checked the oil it was almost 2 ltrs over the top!
anyway meanwhile i quickly changed the valve seals before i noticed the oil level...
since then it still smokes , especially when you rev it...

today i pulled off my exhaust (harris 4-1) to see what cylinders were smoking and its clearly all from cylinder 3.
Ive put a bore scope in and cant see any signs of damage to the piston or the bore itself?

so the only thing i can assume is head gasket?
I don't mind doing a head gasket but don't want to keep throwing money at it if its not.
compression across all cylinders are the same.

any advice will be greatly appreciated.
thanks
J

2 Liters over the max. Is to much oil that can be suck into the combustion chamber.
Do a longer ride with a lower oil level. Clutch cover oil level control Window , oil level between the markings with the bike On center stand

Did you put in the right amount of oil?
Steve

2 liters over the max! Holy cow, I think that's a new record! May I ask why you did that? Ed

Yea it wasn’t me, my friend changed my oil when he was doing his own bike...
Anyway I dropped the oil and done it again

But still smoke from cyl 3??

With a friend like that ...................................

Well, checked everything I could and couldn’t find anything!
So took the head and barrels off today.
Again no signs of wear or damage...
Just to be safe, having the head cleaned
Skimmed and tested tomorrow morning.

All new gasket and we’ll try again.

I’ll report back but has anyone got any ideas?

Damaged oil control ring .
Improperly installed oil control ring
Worn oil control ring
Since you said compression is good and or equal when you tore it down also make sure all rings are indexed properly so oil and or compression doesnt sneak past rings
Dave

Don't forget valve guide seals.
Steve

Sorry been quite....
Done a whole lot of work -
Head and barrels off
rings
barrel gasket
Head was crack tested, light skin
Inlet seats - all valves lapped.
Head gasket

Then since obviously the valves were done the shins where all too tight. Got round that with what I had but now there a little loose but bike started up straight away...

So been riding now problem, smoke gone and had good power.
Although it would sometimes ‘pfttt’ back through the pod filters, and (not just when it ‘pfttt’)
But it would run terrible! Engine noise and spluttering all over the place. Got to work, left it and when I left work it wouldn’t start... after about 20minutes it run badly but I headed home... got 5 minutes Home and it picked back up and ran perfectly fine again and has been for the last couple days... till last night it went back to rubbish!?

So I would say timing but that’s defiantly right and the timing chains good and tensioned.
So maybe weak? But why is it changing between good and rough whenever it likes?

I’m stumped

Check spark now and when running poorly.
Bad connection ,
Bad coil.
ect/ electrric problem
Might be fuel , but electrical needs to be looked at to prove all ok
check manual
DaveB)

SWest wrote: Don't forget valve guide seals.
Steve

That's what my KZ900 had - bad valve guide seals - and it did the same thing.