Got a Head Oil leak!

Hello Gents

I pulled my 74 850 engine last week and replaced it with another engine from a 73 850 to use in the interim. I want to rebuild the 74…. Which had many oil leaks and the right hand cylinder is fouling up with oil on the plug and a worn out cam.
So here is the situation. The 73 was fired up and tested in the original bike and all was well. Pulled it and placed it in the 74 frame, installed Dave Taylor head steady and changed oil to AMSOIL synthetic M/C oil with a bit of Redline Engine oil break-in additive…. lots of ZDDP. , New filter and new Maney belt drive, 21 tooth sprocket and 520 x-ring chain all at the same time.
So I fired it up with the top oil banjos loose and waited till I saw oil. Stopped the engine and tightened them up tight. Restarted the engine and checked oil tank return and then tightening up the exhaust nuts while engine was running. Adjusted the Amals to Idle evenly at 1000 RPM and checked vacuum between the two cylinders and adjusted till they are matching. Now I am getting a oil leak between the 5 and 6 fin down at the head. This engine has not been run for a while and I always used 50 wt in it when it did. In about 5 minuets I have a dollar size puddle dripping on the garage floor. I tried to re-torque the head but to no avail. What do you think? I think a new head gasket. The leak is between the exhaust. I am suspecting the two nuts and the # 1 torque sequence bolt at the front.

Sure the straightest path to take is pop the head and put in new head gasket.
A flame ring rather than copper best chance of seal, just do a retorqe after a few miles.
Easy on throttle until retorqe or you can blow gasket. Don't ask why I know.
Maybe change of oil type is cause since you did absolutely nothing to the engine except swap it.

Oil past rocker cover studs. Blow by from rusted rings scoring bores jetting past gasket and push rod tunnel oil ways. Would see white smoke if that. Spindle covers. Head crack finally reached all the way through. Good luck finding an old school flame ring. I'm all ears if ya do.

Check rocker shaft (spindle) covers for tightness and gaskets. They need to be pretty tight. High pressure oil is present there. If leaking, the oil will trick you by going down to a central canyon in the head behind the plugs and vertical fins which then leads to the front fins you speak of.

Mine had a waterfall of oil there when first fired up after a valve job. Missing a gasket.

batrider said:

Check rocker shaft (spindle) covers for tightness and gaskets. They need to be pretty tight. High pressure oil is present there. If leaking, the oil will trick you by going down to a central canyon in the head behind the plugs and vertical fins which then leads to the front fins you speak of.

Mine had a waterfall of oil there when first fired up after a valve job. Missing a gasket.

Click to expand...

Well Batrider and Hobot got it right. Sorry Hobot I checked only some of the rocker shaft covers and it was dark. Today I fired it in the bright sunlight... (Best light bulb in the world) and low and behold the right hand intake was the culprit. Just glad I don't have to pull the head. 8) If you are going to the Norton Rally in Vermont in July. Search me out and I will by you guys a beer.
Cheers.
CNN

Same one as on mine. I didn't see it right away either. I was so glad I didn't have to take off the head again!

I will be at the rally and looking forward to seeing you guys there. I met the 'bot at the last one. Beer.. well OK I guess.


Russ