Topic: Please help with top end o rings on 78 cb750f

[greenninja85]

I'm putting the top end back together on 78 cb750f and I'm having trouble remembering which o rings go where exactly. I got a new gasket set as well. At the base of the cylinder I know there's 6 o rings that go on the bottom and I know which two go on the inner back studs but those 4 outter ones I'm not sure about. There's 5 little o rings that seem to be right cuz the rest would be to big. But on top of the head I need 4 little ones the same size. So why 5?  Am I missing 3 more?  I would appriciate any help cuz I'm moving soon and would like to move my motor assembled instead of in pieces. Thanks!

[madmtnmotors]

Okay, the four outer o-rings at the base of the cylinders (between the cylinders and the case) ARE NOT included in ANY gasket kit. Also, Honda no longer distributes these for the CB750F2/F3. Good news is they still use these o-rings in their outboard and lawnmower engines.

There's this thread:

http://forums.sohc4.net/index.php?topic=113672.msg1300662#msg1300662


That is about the second result when using the Google custom search at the top left for "5.5 o-ring":

http://www.google.com/cse?cx=partner-pub-9323359806520211%3A1305160748&ie=UTF-8&q=5.5+o-ring&sa=Search&siteurl=forums.sohc4.net%2Findex.php%3Faction%3Dprofile%3Bu%3D11029%3Barea%3Dshowposts%3Bstart%3D150&ref=forums.sohc4.net%2Findex.php%3Faction%3Dprofile%3Bu%3D11029%3Barea%3Dshowposts%3Bstart%3D125&ss=4181j2122889j10#gsc.tab=0&gsc.q=5.5%20o-ring&gsc.page=1

These little o-rings are fat little suckers, 2mm thick.