I inventoried the top-end kit (part# 06110-390-501) I got a few years ago and compared the part numbers of each item within the kit with part numbers on a parts fiche. I have in hand the following:
1 base gasket
1 head gasket
1 12391-323-000 head cover gasket
1 12329-323-000 breather cover gasket
4 18291-390-306 copper exhaust gaskets
2 91310-426-000 O-rings oil control valves, between the case and the cylinder block
2 91301-426-010 O-rings dowels between the head and the cylinder block
4 91319-323-000 O-rings rocker end cap
12 91302-001-020 O-rings (4 for intake manifolds & 8 for the tappet covers)
Some strange things:
1 91310-426-000 O-ring ?? and extra oil control valve O-ring??
4 black O-rings, approx 3.5 inches, no part number. Could these be the rings under the base gasket (part# 91304-286-000)?
8 small green O-rings, no part number, approx 12mm
Looks like I will need to order the six 91318-300-013 "Sealing Rubbers" (aka pucks) as they are not in the kit.
A couple of items I don't quite understand. Is there a reason I should need a third O-ring for the oil control valves? Any ideas what the 8 green 12mm O-rings are for?
If, by "oil control valve", you mean the oil metering orifices that feed the cam bearings: there are several sizes of O-rings on those darn things. Match up the ones you have to new ones. I have the following 3 sizes in my notes for those things:
5.8 x 1.9 mm #91305-323-000
3.7 x 1.7 mm #91317-300-003
5.6 x 1.9 mm #91318-ME5-003
but, these are all for "K" engines. I'm guessing that the situation is similar of the "F" engines, with oil orifices of two kinds that seem to come and go in production. This is one of those little things that I've never figured out: why Honda would switch oil orifices for no apparent reason, requiring a different seal rings in the heads to do it?
Those big, skinny O-rings are for the bottom of the cylinders. Pressing them in and getting them to stay there while you reassemble requires that the old ones be removed and the grooves be well cleaned, like with brake cleaner, so the new ones will 'stick' into the grooves. I press them in with the side of a small flat-blade screwdriver, going around a little at a time until they are evenly seated. Then they will stay. If you start in one spot, the rest won't go in evenly, and it will creep back out.
Those green 12mm O-rings are for K2 and earlier engines: they go in place of the longer ones that look like dowels, as those earlier engines didn't have the deep recesses alongside the dowels between the head and cylinders (the recesses were cut into the cylinders).
I might suggest: take the cylinders and the head to a good engine shop, and ask to have the mating surfaces ground flat, if you suspect the leak was coming from between the head and the cylinders. Usually, though, the leak comes from the pucks, and works its way out of the area between the head & cylinders. I ALWAYS glue the pucks in, with either FelCoBond (from Fel-Pro) or the thin paint-on Aviation Gasket Sealer from Permatex. I used to use the non-hardening Permatex, but in this hot zone, it still hardens after a lot of miles. The other stuff never hardens, seals better. Don't use silicone sealers here, they won't work in this spot.
The rings: don't remove them from the pistons unless you plan on installing new ones. You can infer the ring gap wear by taking a NEW 3" hone (Checker or Auto Zone, $8 or so) and spinning it in the bore for about 30-60 seconds or so. This will scuff the glaze on the walls and will show where the "ridge" is at the top of the cylinders: that 'ridge ring' will still be shiny. If you have any inside-measuring bore tools, measure at the deepest spot and compare to the unworn bore near the bottom of the cylinder. The ring gap can be inferred by multiplying the ridge depth by 3.14 and adding that to Honda's spec .003" (example: (.0005" wear x 3.14) + .003" = .00457", still within the .006" limit). If the ridge is more than .003", I'd suggest an overbore (not likely at 30k miles). If it is less than .0005", leave the rings alone, just reassemble. If it's in between, consider new rings, of the same type (go by the oil rings, 1-piece or 3-piece), but hone the bores a little more until the ridge ring is minimized or gone (typically about 3 minutes honing time, clean the stones with kerosene/charcoal lighter fluid/Coleman fuel between bores). Then, take one of the old rings of each type, break it, and use it to scrape out the carbon from the piston grooves before installing the new rings. This will take a couple of hours, but isn't a terrible task.
The biggest problem I see with the Haynes suggestion of checking the ring end gap of your old rings: they will distort if you remove them from the piston. This will ruin their mated seal. So, you must hone the cylinder afterward to re-wear that seal, which will leave you with an extra .0005" or so clearance after they do re-mate, which means loose rings and larger end gaps, which will flutter and seal poorly. So, if you remove the rings, install new ones and hone again. I just bought some MC rings on eBay for $7 per bore (these are the 1-piece oil rings, though), and they were good rings back in the day. They have a stepped 2nd ring, which seals a bit better at high RPM, compared to the stock 2nd ring.
The toughest part, reassembling the pistons into the bores, can be greatly eased if you also take some time to sand the sharp edge of the bottom of the bores with some 100-150 grit paper, and round that edge. You'll prevent a ring snag on those 3-piece oil rings a whole lot better, if you do this now.
