If the o-ring is being "spit out" - then you're looking at one of the surfaces being warped...

Check the mating surfaces with a flat-edge...any irregularity should show itself...

All OK? Then...

Put a thin bead on both sides of the gasket, assemble the parts and let the repair SIT 'til the sealant (according to the directions) has a chance to cure completely, first...

Once that's done, THEN start it up.

Don't run the engine 'til the goo cures...

__________________

M. G. Burg
'10 - Dakota SXT - Daily Ride / ≈ 172.5K
.'76 - 450SLC - 107.024.12 / < .89.20 K
..'77 - 280E - 123.033.12 / > 128.20 K
...'67 - El Camino - 283ci / > 207.00 K
....'75 - Yamaha - 650XS / < 21.00 K
.....'87 - G20 Sportvan / > 206.00 K
......'85 - 4WINNS 160 I.O. / 140hp
.......'74 - Honda CT70 / Real 125
.
“I didn’t really say everything I said.”
. . . . . . . . . . . . . . . . . . ~ Yogi Berra ~