Re: Head / barrel oilway o-ring
Posted: Tue Mar 08, 2022 7:53 pm
Hans
I would agree that Viton is essential for the Desmo guide O ring (same size). However the originals were Nitrile as they went rock hard after years of use. Anyone who's ever tried to remove a guide O ring after years of use will know what I mean, not easy! There are certainly no disadvantage in using Viton O rings of the same hardness, only cost...which is nothing in real terms. Regarding the colour of Viton seals, many are supplied as black, so it is not a hard and fast, green or brown identification with all makes. Mentasti used to supply Ducati with green guide seals, which are in there catalogue as green.....but now come supplied black. The Viton O rings we supply for the Desmo guides are also black.
Geordie,
Sorry if I missed the "clean oil" bit, I would then suspect a bango or top bevel gasket. Is the banjo face distorted and does it have unflanged bolts? If all is flat, alloy washers should seal it well. However if the faces are less than perfect, you may need a little sealant, or some other parts.
Regards Nigel
I would agree that Viton is essential for the Desmo guide O ring (same size). However the originals were Nitrile as they went rock hard after years of use. Anyone who's ever tried to remove a guide O ring after years of use will know what I mean, not easy! There are certainly no disadvantage in using Viton O rings of the same hardness, only cost...which is nothing in real terms. Regarding the colour of Viton seals, many are supplied as black, so it is not a hard and fast, green or brown identification with all makes. Mentasti used to supply Ducati with green guide seals, which are in there catalogue as green.....but now come supplied black. The Viton O rings we supply for the Desmo guides are also black.
Geordie,
Sorry if I missed the "clean oil" bit, I would then suspect a bango or top bevel gasket. Is the banjo face distorted and does it have unflanged bolts? If all is flat, alloy washers should seal it well. However if the faces are less than perfect, you may need a little sealant, or some other parts.
Regards Nigel