Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
5 x 2.4 according to the Parts book in Aladdin's Cave on here.I used a slightly bigger thickness Viton O rings on my CB550K2, with an aftermarket head gasket from David Silvers, and it never leaked again.Hope this helps,Brian.
Quote from: Brian. on August 24, 2021, 02:18:31 PM5 x 2.4 according to the Parts book in Aladdin's Cave on here.I used a slightly bigger thickness Viton O rings on my CB550K2, with an aftermarket head gasket from David Silvers, and it never leaked again.Hope this helps,Brian. How many km since?
Further to the above, I've been through my Ebay purchase history at my O-ring purchases. Based on the Honda standard thickness of 2.4 and what I bought around that time, they would either have been 2.5mm Viton (which I doubt because it's hardly any thicker at all) or 3.0mm Viton. I'd say it's 99% definite that I used 3.0mm, which makes sense to me today as a proper thickness upgrade. And mine definitely didn't leak again up to when I sold it.But, you would be far better advised by Nurse Julie's experience than my recollections!I hope this helps.Brian.