oil leak front head area

[RobC]

I got an oil leak on my front cylinder. I've changed the rocker gaskets but its still weeping. Any ideas?
It seems to be coming from the square air vent hole in the rocker cover but I can't say for sure. Ah, would the wrong oil filter cause this?

[Tony Cross]

What have you done? Put a twin cam one on???

[dodgyloner]

Originally Posted by RobC

would the wrong oil filter cause this?

Very unlikely I would have thought. There is about 1-2 psi air pressure inside the engine casings when its running. The air will be forcing oil out through a gap.

If its coming from the square vent hole there is only one small square gasket in between the top and bottom covers. Suggest you remove, clean and reinstall the top two covers. I always stick the gaskets in with grease to make sure they dont pop out whilst installing the covers. Tighten em each down gradually in a cross ways pattern.

If this fails try some Hylomar.

[girlyglide]

Unusual for it to leak on the center seal. It could be dislodged or not seated correctly. You could also check the rocker covers for warping.

[RobC]

Originally Posted by girlyglide

Unusual for it to leak on the center seal. It could be dislodged or not seated correctly. You could also check the rocker covers for warping.

That was an answer I suspected but didnt want to hear.
Gaskets greased to hold in place before tightening.
I put the screws down cross ways pattern.

Is there any place lower down it could be leaking in the below rocker cover area?
It's very little oil but it makes such a mess.
I aint had to wear wellys when riding a bike since the 70's and the Mrs is playing balls cos of oil stains her boots.

[dodgyloner]

The gaskets between the bottom rocker cover and the cylinder head can go occasionally - in my experience this creates a fine spray at speed which goes everywhere.

Gaskets are cheap but are a bit of a nightmare to do as you have to disturb the rocker arm assembly. Not to be attempted without factory manual as, if I remember rightly, there is a sequence to bleed down the hydraulic lifters when reassembling the bottom rocker cover to the head.

[kiwidave]

Warpage of the rocker box components is not unusual. I had the same issue a few years ago. The answer is a sheet of glass (check them on that and if they are warped, then.....) some valve-grinding paste, and some elbow grease....

[RobC]

I've sorted the leak.

I removed the rocker cover again to inspect and replace the o-rings.
The new o-ring dislodged and twisted causing a real bad leak.
I ordered new o-rings and in the mean time I decided to change the head to rocker gaskets.
When slacking the studs off I found that one stud was loose. The gasket was oil soaked. I fitted the new gasket and torqued everything down.
I fitted the new rubbers and glued them in place with a little silicone gasket.
I let everything set.
I put it back together this lunchtime and Hay Presto no more leak.

So, for future reference. Check the rocker studs for tightness, dont think its just the o-rings

[kiwidave]

And for future reference, and this does assume I read your post correctly....do not EVER use silicon goo ANYWHERE in the engine. Really. It just takes a little bit to fly off and clog one oil way, and that's what happens....and you are up to your neck in rebuild $$$$$.

It's OK around the primary if you need to, but NEVER anywhere near rockers, cylinders, oil pump, pushrods, lifter blocks, nosecone, etc..... I know you ''let it set'' - but you can't see the Murphy Fairies emerging when it is all bolted back together.