Topic: cb500 unknown o-ring in top end rebuild

[kurtkarram]

Hey everyone I'm in the middle of a top end rebuild on my 1973 cb500. I have the gasket kit from 4into1.

In there, there are 8 small green orings. On their website it says it goes on both intake and exhaust valve guides. However, I do not see this anywhere in the videos of valve lapping, and Matts howtomotorcyclerepair top end video. I also do not see it in the parts diagram anywhere.

Part number is 91301-200-000

Can someone confirm where this goes? Or that it's not needed? Thanks

[wolf550]

I think I remember finding those under the intake and exhaust valves when I took a set out of a broken cylinder head

[C317414]

Check out item#15 here:

https://images.cmsnl.com/img/partslists/honda-cb500k2-four-1973-usa-cylinder-headcamshaft_bighu0102e3002_b8f9.gif

[newday777]

Hey everyone I'm in the middle of a top end rebuild on my 1973 cb500. I have the gasket kit from 4into1.

In there, there are 8 small green orings. On their website it says it goes on both intake and exhaust valve guides. However, I do not see this anywhere in the videos of valve lapping, and Matts howtomotorcyclerepair top end video. I also do not see it in the parts diagram anywhere.

Part number is 91301-200-000

Can someone confirm where this goes? Or that it's not needed? Thanks

As the CMS picture shows C317414 posted, they go in the head under the valve guides.
Did you replace the valve guides? If your valve guides are not being replaced, you won't find them on your motor......
I've included the part number in my picture to confirm.

[Tim2005]

Yes you won't need them unless you are changing the guides. However, don't throw them away, I recollect they are the right size to fit the front brake caliper pivot.

[newday777]

Yes you won't need them unless you are changing the guides. However, don't throw them away, I recollect they are the right size to fit the front brake caliper pivot.

Interesting