Thank you MCRIDER. All your advice was accurate. By the time I read it however, I had already gone ahead and pried it out with a dull small screwdriver, dinting the edge just like you said, reformed the edge carefully, cleaned it in solvent and gently pressed it back into place. Some gentle pressure is required to put it back, but now that it is in there, I don't think it is going to come out by itself.
Ta Da! There you go, you've done something that many others have never attempted. Glad to know it popped back in OK. I thought it should.
MC:
Would you estimate that the O-ring might be something that we could replace with a new one? Just curious...I've been spending a lot of time with the local seal house, finding common O-rings that cost half as much as Honda's for these engines. (I'm working on 6 engines, O-rings are getting expensive!)
I have now a whole BAG of the O-rings for the little valve caps. I use them on bikes that come by for a tuneup and have hard, leaky ones. Honda's peculiar size callout seems to be for O-rings that were custom-made to reduce the amount of material (and thus their costs on thousands of bikes) to a minimum level: I have found superior tranny performance, for example, by using an O-ring of .1mm extra thickness on the countershaft bearing holder where it feeds the oil to the mainshaft gears. The one that came in the Vesrah kit was the same as Honda's (a 2.4mm cross-section) here, and after 20k miles it was shrunk enough to leak a little again: as soon as I installed this new one and rode about 50 miles, the difference was apparent.
This same scenario applies to the ones on the 550 oil pumps and 750 oil pumps and hoses: those have a callout of 2.4mm cross section, and the 2.5mm ones increae sealing face size by 2.5% and pressure by almost 5%, still well within the squish callouts recommended by the O-ring manufacturers (18-23% squish for seals).
My goal, here, is to provide superior sealing for use with synthetic oils. I have found several weak sealing spots on my K2 with the Mobil 1, but like the performance so much that I want to stay with it: so I'm improving the seals everywhere (just so I can go back and add it to my book, now that the section was already finished...
). The cam cover, after about 5k miles and a new (almost new) oil pump, started leaking (it has the Yamabond), so I'm going to attempt the Aviation Permatex paint-on up there this next time. You have to apply it 4 times: once to the gasket and cam cover, dry a little, stick together, repeat with the other side. (No wonder airplanes cost so much!)