Base Gasket Problem?

[Blackseven]

A couple of weeks ago I had to remove the head from my newly built engine to get one of the exhaust stud bosses welded. I didn't replace the base gasket as I didn't disturb the barrels. The head was off for about a week. When I torqued the head (new head gaskets) I could see oil oozing out of the base gasket, it looks like oil has seeped across the face of the base gasket when the head was left off and I'm worried in case this makes the base gasket more likely to leak in the future? The base gasket is a Vesrah and was originally fitted with a smear of grease on the faces.

If I've got to replace the base gasket I'd rather bite the bullet and do it now whilst the bike is only partially built, but don't really want to remove the head (again) if I can help it. I'd be really grateful for any advice and thoughts as to how much more likely the base gasket is likely to leak? Cleaned up it obviously looks OK now.

Thanks in advance for the continued wisdom of this forum!

Rob

[zed1015]

A couple of weeks ago I had to remove the head from my newly built engine .
I didn't replace the base gasket as I didn't disturb the barrels.
When I torqued the head (new head gaskets) I could see oil oozing out of the base gasket, it looks like oil has seeped across the face of the base gasket when the head was left off .
The base gasket is a Vesrah and was originally fitted with a smear of grease on the faces.
Cleaned up it obviously looks OK now.

I think you have answered your own question there and it's just oil that was squeezed out of the joint when the head was torqued down.
In this situation with a fresh greased gasket it's very unlikely it will leak and the oil wouldn't make a difference to the gaskets effectivness..

[Wrigers]

Im no expert on this matter, but im in a similar position myself. If you take a look at my earlier post re VALVE SEAL, there's a comment on there from Al re oil seeping across the base gasket when you remove the head. Just food for thought.......

[Blackseven]

It was the earlier post regarding re valve seal (and the comment about oil coming across the face of the base gasket) that got me thinking.

Thanks for the reassurance zed1015; you have confirmed my initial thoughts. I think I'll leave be and keep an eye on it.

Rob

[Al]

If you greased the base gasket and it wasnt leaking before you removed the head then i would guess; no harm done. Oil / grease similar thing. I put mine on dry and they are impregnated with wax which sticks the gasket to the crankcases and the barrels. When iv'e removed the head and tried not to disturb the barrels and oil has come out it is because i have damaged the gasket, de-laminated the fabric, or partially peeled it away from one face. I could not then guarantee that the wax impregnation of the gasket could be relied upon to make a comprehensive seal all round and have errred on the side of caution and replaced it. It is a faff but having gone that far i dont want it leaking and having to re-visit that task. Of all the gaskets on the engine, those that have given the least trouble are; the base gasket and oddly the sump gasket but they are a basta%d to remove when that time arrives.
One thing that may be worth bearing in mind is that the front barrel studs seem (on mine at least) to collect a great deal of very fine grit particles between them and the holes they run through.. If you were to lift the barrels a couple of mm then this may drift onto the gasket face!!!

AL

[Blackseven]

Great advice as always from this forum. thanks.