Topic: cylinder head o rings

[aceospades]

new to the forum. hope i can lend as much advice as I receive. However, this topic is me on the back foot. can anyone describe exactly where and what size o ring fits with the cylinder head gasket.

[Frostyboy]

Welcome to the forum. You didn't say for what bike, however if it's a 550 by any chance I'm pretty sure it's 4.9x2.5 Part# 91301-426-010 You need 2 of them

[MCRider]

If its a 750, we need the engine ID number as the size and quantity of ORings changed.

[aceospades]

Sorry I did forget to include the engine size. It is a 550 and not the 750. I have taken the head back of and I had indeed missed putting them on. The result if which made cylinders 123 burn oil. The problem I remember at the time was the picture in the Haynes was confusing. I seem to remember when intook the head of first time around, the orings were not around the dowel but were positioned on the oil passage. In any event I missed it.

[Frostyboy]

I'm not aware of o rings being necessary around the dowels. They are to seal the oil passages to the overhead gear. In any event, I can't see how they would cause 3 cyls to burn oil.
Perhaps there's more going on here. Did you renew the valve stem seals when you had the head apart?

[Danno]

frosty the 550 uses a high pressure oil  system and I have never had it be as bad as he describes but the lack of orings and a slightly warped head could do it my bike hits 80 psi which is one of the reasons the 550 loves to weap a little oil at the sides of the head when those orings get old and hard

[aceospades]

I had the head skimmed and the deck planed. New stem seals and orings to the stem seals. I installed the o rings to the oil restrictor under the block. What I didn't do was install any o rings at cylinder head level. When I removed the head again oil had entered the three cylinders 1 being the worst and 2 being not so bad. 3 had oil contamination but not as bad. Oil had found it's way from the oil passage by either capillary action or just high pressure. I did notice as well that the head bolts were no where near as tight as I had torqued them above the oil filled bores. I have ordered 4.9 x 2.5 o rings and a new genuine head gasket and will install. The Haynes manual gave no reference to an oil seal at the oil passage so I missed it out

[Frostyboy]

Sorry I did forget to include the engine size. It is a 550 and not the 750. I have taken the head back of and I had indeed missed putting them on. The result if which made cylinders 123 burn oil. The problem I remember at the time was the picture in the Haynes was confusing. I seem to remember when intook the head of first time around, the orings were not around the dowel but were positioned on the oil passage. In any event I missed it.

Sorry, it would appear I misread this message. I thought you were blaming the fact that you didn't have orings around the dowels. My mistake.