Oil leak from front cylinder head/barrel

[ernie]

A spring balance - obtainable at any hardware shop - reading 0-50 lbs - on the end of a 9" open ended spanner at 90 degrees to the axis of the spanner. Reading 40 lbs on the balance is 30 lbs ft. at the nut.

 

[danno]

Before you do anything drastic try swapping the front exhaust rocker inspection cap for one of the others, plus a new washer of course. I don't know why it should make a difference but it did on mine when I had a similar problem. Curiously the cap did not leak in it's new position (inlet rocker - different bike).

I've swapped the cap over and cleaned off the oil.I'll see how it goes.
Thanks

 

[danno]

Thanks for the other replies.
Not sure if I have a spring balance or even what it is.
May be one in the garage amongst all the tools.
Not going to try anything till I'm sure though.

 

[ernie]

Spring balance - cheap

http://www.toolbox.co.uk/silverline-250387-spring-5083-84921

 

[tatty500]

Tatty500

Danno?
No one has stated the obvious....unles I missed it.
The only real seal at the head-barrel joint is on the top of the liner. There is not necessarily a real seal between the aluminium top of the barrel and the head.
Oil can come up round a headstud from the crankcase and come out at the joint.
Also, like on my old B, the barrel casting can be pourous. Mine oozes oil about three fins down from the joint. I don't know if it gets there round the liner or up the front left stud.
Finally, the thread in the deep headnuts ET56 is often half a thread too shallow. This can cause the nut to bind on the thread just at the point of actually pulling the head down. This can be diagnosed by trying tio undo the head nut and noticing if it rotates easily on its washer ET152 as the stud twists anticlockwise and before the nut is obvously being undone.

 

[danno]

ThanksWould I need to remove the head to access ET56?I'm assuming the double nuts on the top of the cylinder head are ET154 & 198.Once the rain clears I'll run the bike and try andlocate source of the leak.Danno

 

[tatty500]

Danno,
no, if you just slacken off the 198 and ET154 nuts....these only hold the head bracket down on top of the ET56s.......then each or any of the ET56 nuts under the head bracket can be tightened or assessed for tightness at least.
Raining here too.

 

[tatty500]

Danno,
oops sorry,
of course you probably have one-piece headstuds, so the nut and locknut on top of the head bracket are FT161 and 879. Drawing MO15 shows both types.

 

[clevtrev]

Quite often, this sort of leak, is from the exhaust port, via the nut. The front cylinder being more prone to oil leakage past the piston. Does the front plug have a tendency to oil up ?

 

[Mark Fisher]

Danno, try to avoid messing with the headnuts until you have located the leak. Tatty is right about the head/barrel interface, in fact my Egli "sweats" a bit here but no amount of tightening will stop it. If i want it to stop I'll have to take the heads off and do some remedial work but it is too minor to go to all that trouble as there is no gas leakage and i can clean it off occasionally. My shadow does not have this problem though and yours may not have.
mark